At-Large Legislative Contests in the 2020 Puerto Rico General Election

While most seats in both houses of the Legislative Assembly of Puerto Rico are chosen by plurality (single-seat districts in the House, two-seat districts in the Senate), there are 11 seats in each body – out of a total of 27 in the Senate and 51 in the House of Representatives – that are filled on an at-large basis, by Single Non-Transferable Vote (SNTV). The 2020 election in the U.S. Commonwealth was notable not only for the fact that candidates from five parties secured at-large representation (along with a sitting independent senator), but also for the unexpectedly poor showing of the largest opposition party, the pro-Commonwealth Popular Democratic Party (PPD) in the at-large legislative races.

To be certain, the outcome of the election was nothing short of a political earthquake, with both the ruling, pro-statehood New Progressive Party (PNP) and PPD polling their worst results ever: 33.24% and 31.75% of the valid votes for governor, for a combined share of 64.99%. Meanwhile, the island’s perennial third party, the left-wing Puerto Rican Independence Party (PIP) shot up from 2.13% in 2016 to 13.58%, but the new Citizens’ Victory Movement (MVC) – ideologically diverse but broadly left-liberal – outdid PIP with 13.95%. Another new party, the Christian-conservative Project Dignity (PD) won 6.80%.

Despite their respective setbacks, the two major parties continued to monopolize between themselves all legislative district seats (MVC narrowly lost a House race in San Juan to PNP), with PPD securing a majority of these in both houses despite polling fewer votes than PNP, due to latter’s concentration of votes in the San Juan metropolitan area. So why did PPD fail to do as well in the at-large legislative races? The answer lies in the workings of the at-large representation system in Puerto Rico, known in Spanish as representación por acumulación.

Specifically, since politics in Puerto Rico evolved into a two-party system in 1968, following 28 years of PPD dominance, the two major parties have nominated six at-large candidates each for both the Senate and the House of Representatives in every election (from 1952 to 1968 PPD nominated seven at-large candidates to each legislative body). In order to guarantee each candidate has an equal chance of being elected, parties vary the order in which candidates are listed on the ballot in each of the island’s electoral districts – precintos in Spanish – 110 in total since 2012 (to be increased to 114 in 2024); parties assign candidates a set of electoral districts known as a legislative bloc – bloque legislativo in Spanish – in which they are placed at the top of their respective party lists, and as such automatically receive straight votes cast for their party, which have constituted the majority of ballots in every election; party ticket votes with votes cast for other at-large candidates from the same party are considered split votes. (See sample ballot.)

From 1972 to 2012, PNP and PPD elected four to six at-large candidates each in both the Senate and the House. Nonetheless, over the years an increasing number of voters cast either split ballots or bypassed party tickets altogether and voted for candidates only – in Spanish voto por candidatura – and PIP, which nominated single at-large candidates for each body from 1984 onward, was able to tap into that vote to secure seats for its at-large candidates in nearly every election during that period (the party won no at-large seats in 2008 and only a Senate at-large mandate in 2012). Even so, as recently as the 2012 election 81.27% of valid legislative ballots were straight votes, and the overall impact of split/candidacy votes was comparatively limited.

However, in 2016 split/candidacy voting soared from 18.73% to 35.62% of the legislative ballot valid vote, and the main beneficiary was José Vargas-Vidot, who became Puerto Rico’s first-ever independent candidate to win a legislative seat, securing a Senate at-large mandate and topping the poll as well. In fact, his vote total was made up entirely of split/candidacy ballots, since no provision is made to cast a straight vote for an independent candidate, and his victory reduced PPD to three at-large Senate seats (with PIP winning one and PNP the remaining six).

Although PNP returned to power in the 2016 election, the party polled its worst result up to that point in the gubernatorial election, and PPD its second-worst, with the major parties’ combined share of valid votes declining from 95.56% in 2012 to 80.67%. Meanwhile, independent candidate Alexandra Lúgaro won a respectable 11.13% of the vote, and went on to found MVC in 2019. By then, the marked decline of PPD in 2016, along with the emergence of Lúgaro’s new party and the success of the Vargas Vidot independent candidacy called into question the wisdom of nominating six at-large candidates in 2020, when five might have a better chance of securing election. To that end, a proposal was made to the party leadership, which however was rejected after a former but still highly influential party leader spoke against it, insisting that “too much was in play,” that nominating five at-large candidates instead of six could be perceived as an admission of weakness, and prevent the party from winning an overall majority in either or both houses of the Legislative Assembly.

(In the interests of full disclosure, I should note I collaborated in the proposal calling for the nomination of five PPD at-large candidates, and was present at the party leadership meeting in which it was discussed and turned down.)

As it was, MVC anticipated it would fare at least as well as Lúgaro did in her independent gubernatorial run in 2016, and nominated two at-large candidates for both legislative bodies, using Lúgaro’s 2016 vote as the basis for the corresponding legislative blocs. Meanwhile, PNP and PPD ran their usual six-candidate slates for both the Senate and the House, PIP and PD nominated single candidates for both houses, and Sen. Vargas-Vidot ran for re-election. However, although every MVC, PIP and PD at-large candidate as well as Sen. Vargas-Vidot was successful in the 2020 election, PNP only won four at-large seats in the Senate and five in the House, while PPD won just two at-large seats in both houses, as detailed in the following table (full results are available on my Elections in Puerto Rico website):

House Senate
Party % Seats % Seats
PNP 33.84 5 33.37 4
PPD 36.03 2 31.27 2
PIP 10.56 1 11.29 1
MVC 12.83 2 10.99 2
PD 6.73 1 7.33 1
Ind. 5.76 1

In both the Senate and House at-large races, the combined percentages obtained by all six PPD candidates – 31.27% in the Senate and 36.03% in the House suggested that while securing six of eleven seats might not have been a realistic goal, the party should have done better than winning just two seats (18.18%) in each case. However, an additional complication was that PPD candidates fared quite unevenly, although it should be noted these disparities weren’t due to the makeup of the PPD legislative blocs; instead, the large number of split/candidacy votes – which increased to 40.15% of all valid legislative ballots in 2020 – made the legislative bloc arrangements far less meaningful, as many voters backed candidates who weren’t assigned the top spot in their electoral districts. The uneven performance of PPD at-large candidates on account of split/candidacy votes was particularly evident in the House of Representatives, as shown in the following table:

Candidate Straight Split/Cand. Total
Héctor Ferrer 48,750 93,100 141,850
Jesús Manuel Ortiz-González 52,591 19,359 71,950
Enid Monge 52,031 6,474 58,505
Keyliz Méndez-Torres 48,416 8,827 57,243
Yaramary Torres 48,348 6,774 55,122
Gabriel López-Arrieta 45,817 4,838 50,655

In fact, Ferrer polled 73,213 votes outside his assigned legislative bloc – a figure which by itself exceeded the vote totals of the remaining five PPD House at-large candidates.

Among PPD Senate at-large candidates, the split/candidacy vote total disparities weren’t as marked, but even then the two winning candidates had the largest totals on that column:

Candidate Straight Split/Cand. Total
Juan Zaragoza-Gómez 52,591 21,218 73,809
José Luis Dalmau-Santiago 52,031 19,865 71,896
Aníbal José (Jossie) Torres 45,817 15,385 61,202
Brenda López-De-Arrarás 48,348 11,613 59,961
Ada Álvarez-Conde 48,750 8,470 57,220
Luis Vega-Ramos 48,416 6,234 54,650

Another factor at play is that many voters don’t understand the workings of SNTV, and for one reason or another cast their votes under the incorrect assumption they can vote for up to six candidates in each legislative body – as if it were a Multiple Non-Transferable Vote (MNTV) election – instead of only one. Ballot design might be at play, as at-large races are the only instance in which the number of nominations doesn’t go hand in hand with the maximum number of votes a voter may cast, but the fact is that both PNP and PPD actually use MNTV in their internal party primaries to choose at-large nominees, and many voters – sometimes including even seasoned political analysts – mistakenly assume that system is also in place for general elections, ballot instructions to the contrary notwithstanding.

The introduction in 2016 of vote counting machines providing detailed overvote and undervote statistics highlighted the confusion surrounding the way in which at-large legislators are chosen. Specifically, although overvoting in at-large legislative races, while somewhat reduced in 2020 (due to the efforts of how-to-vote campaigns from civic groups), is still significantly higher than in district races chosen by plurality voting, where it remains negligible (even though the vote counting machines are supposed to warn the voter about overvoting and undervoting). Besides overvoting, some PNP or PPD voters back third-party or independent at-large candidates under the assumption they are giving just one of six votes to such candidates, with the remaining five votes they think they have (but really don’t) going to the rest of their preferred party slate, when in fact they are giving their sole vote to a candidate outside their party.

Another issue in at-large legislative races is the so-called invasion of electoral districts, in which major party at-large candidates actively campaign for votes in electoral districts that don’t belong to their assigned legislative bloc, fully aware they are taking away votes from fellow party candidates. Suffice it to say this is a very sensitive matter, and there’s no information to confirm whether or not it took place in 2020.

It should also be noted that the 2020 general election in Puerto Rico was carried out under a new electoral law imposed unilaterally by PNP just months before the election, over the objections of opposition parties. One of the more controversial provisions of the law granted the ruling party near-absolute control of the Elections Commission, which had been run on a power-sharing basis among registered parties since a major reform in 1983 (following the disastrous 1980 election, in which the Elections Commission had been under PNP’s full control as well). While there were few issues with in-person polling, either election day or advanced, the tally of the bulk of advance/absentee votes in special polling station 77, mainly domicile and mail-in votes, accounting for about one-eight of all ballots, proved to be extremely problematic from the beginning, not least because its ten-fold expansion under the new electoral law overwhelmed the agency. To this day the exact number of voters requesting advance ballots in 2020 remains unknown, the results of polling station 77 are riddled with discrepancies – often quite significant – in every electoral district, and some believe the cited issues might have adversely affected PPD in the at-large contests. However, PNP leaders insist there is nothing wrong with the electoral law, and to date have resisted attempts to reform it ahead of the 2024 general election.

At any rate, the decision by PPD leaders to nominate six at-large candidates in 2020 for both houses proved to be a monumental blunder, which had the effect of exposing the very weakness that party leaders desperately wanted to conceal; in practical terms it resulted in a Senate in which no party had overall control of a legislative body for the first time since 1940; PPD won a plurality of Senate seats and an overall majority of one in the House.

But would PPD have been better off by nominating five at-large candidates instead of six? According to a Senate-only, post-election simulation I ran with five candidates, the answer is affirmative: at least four candidates, and possibly all five would have been elected. Even so, it’s by no means certain PPD will nominate in 2024 five at-large candidates instead of six, not least because many party leaders remain in denial about the major changes in voting trends that took place in 2016 and 2020, insisting they are nothing more than a transient phenomenon. That said, it’s worth remembering that in Spain it took several years for PP and (to a lesser degree) PSOE leaders to finally come to terms with a similar shift away from two-party dominance after 2015.

Finally, from time to time some PNP and PPD leaders have called for the elimination of at-large legislative seats, thus resulting in a Legislative Assembly elected in its entirety by plurality in districts. However, such calls appear to be motivated by a desire to get rid of independent and third-party legislators; that such a move could backfire in future elections in which either PNP or PPD, or both might no longer be major parties appears not to have been considered at all. And while leaders of both parties might scoff at such prospects in the here and now, they cannot be ruled out altogether in the long run, all the more so since as a result of their steady decline the two major parties appear to be increasingly dependent on the support of old voters, much like CDU/CSU and SPD in Germany’s 2021 Bundestag election. In fact, in the 2020 general election PNP and PPD won between themselves 87.71% of the advance/absentee vote in the gubernatorial race, 85% of which came from voters aged 60 or older; but among the younger election day voters they polled just 60.68% between themselves. All the same, doing away with the at-large legislative seats would require amending the Constitution of Puerto Rico, and for the time being it does not appear such an amendment – which would have to be approved by voters in a binding referendum – will be forthcoming.

The 2018 Ranked Choice Voting Election in Maine’s Congressional District No. 2

Maine’s recent congressional election – the first-ever federal poll in the U.S. to be held under Ranked Choice Voting (RCV) – took place against a backdrop of continuing opposition by the Republican Party to the recently introduced voting system. State GOP leaders not only called on their voters to rank just the party’s candidates, but sought as well a court ruling to prevent RCV from determining the outcome of the U.S. House of Representatives election in Congressional District No. 2, and subsequently a recount of all ballots in the election (later called off while it was underway).

Nonetheless, a significant minority of Republican voters in the district ignored party exhortations and indicated valid rankings for at least two candidates, while substantial minorities of non-GOP voters only gave a first preference to Democratic or independent candidates. At the same time, the number of voters who engaged in bullet voting – indicating a preference for just one candidate – constituted a minority of the voting electorate in CD-2. This is notable when one considers that in both the 2016 and 2018 RCV referendums held in Maine, a majority of voters in CD-2 rejected the switch from plurality voting.

Moreover, a federal judge first allowed the RCV count to take place, and subsequently issued a ruling upholding the constitutionality of the election in the congressional district, where incumbent Republican Bruce Poliquin obtained the largest number of first preference votes, but fell short of an absolute majority; he then lost the second and final round of counting to Democratic challenger Jared Golden, who prevailed with 142,440 votes (50.6%) to Poliquin’s 138,931 (49.4%) following the elimination of independent candidates Tiffany Bond and Will Hoar, whose second preferences were transferred to the remaining two candidates. The First Circuit Court of Appeals subsequently denied Congressman Poliquin’s motion for an injunction to prevent Golden from being declared the winner, and Poliquin – who wanted the election outcome determined solely by the first preference count, or by a re-run under plurality voting – dropped the lawsuit challenging RCV shortly thereafter.

The following table, based on a tally of 296,077 cast vote records in CD-2, published by Maine’s Secretary of State on his official website, shows the distribution of first preference votes for each candidate with at least a valid second preference for another candidate (“Preference”), or no second and successive preferences for a different candidate (“Bullet”); the “Other” category groups ballots with valid first preferences, but no valid second or successive preferences due to either overvoting on the second preference ranking – indicating a second preference for more than one candidate – or undervoting i.e. leaving blank more than one consecutive ranking beyond first preference while indicating preferences for other candidates, or a combination of both. State of Maine 2018 Ranked Choice Voting (RCV) Election Data has frequency counts for all 1,564 tallied preference combinations in the CD-2 election.

Candidate Bullet % Preference % Other % Total
Bond (I) 4,333 26.2 12,106 73.1 113 0.7 16,552
Golden (D) 51,423 39.0 79,551 60.3 1,039 0.8 132,013
Hoar (I) 2,120 30.8 4,713 68.6 42 0.6 6,875
Poliquin (R) 89,228 66.5 43,955 32.8 1,001 0.7 134,184
Total 147,104 50.8 140,325 48.5 2,195 0.7 289,624

There were 435 overvotes and 6,018 undervotes in the first preference count; the latter figure – which included 5,711 ballots undervoted on all available rankings – is noticeably lower than the reported number of blank ballots in the plurality-based 2014 and 2016 U.S. House elections in CD-2, and it is also lower than the number of blank ballots in the district for this year’s gubernatorial election in Maine, which was also carried out by plurality voting. At the very least, these numbers indicate the introduction of RCV did not bring about an increase in the number of blank or invalid ballots. In addition, the very low number of overvotes strongly suggests there was little voter confusion about the new electoral system.

Of the 147,104 voters in CD-2 who indicated valid preferences for just one candidate, 137,971 indicated only a first preference, including 315 cases with a second preference but no first preference, while an additional 9,133 voters indicated a valid first preference (or a valid second preference without a first preference), as well as additional preferences, but only for a specific candidate; a large majority of these – 7,706 voters – gave all five preference rankings to their chosen candidate. Under Maine’s RCV counting rules, these votes had the same effect as having indicated only a first preference for the selected candidate. However, while ballots with valid preferences for just a single candidate constitute a narrow majority of the valid first preference votes, they represent a minority of 49.7% of all votes cast in the district. By contrast, in both the 2016 and 2018 RCV referendums, CD-2 reported a majority of votes against RCV both among the valid and overall vote totals. Moreover, even among voters casting valid first preferences, those who indicated a first preference only were a minority of 47.6%.

Bullet voting for the two major-party candidates had no impact in the CD-2 election outcome, since their first preferences were tallied in the second count as preferences for continuing candidates. However, the 6,453 ballots with valid rankings for either Bond only or Hoar only made up the bulk of the 8,253 non-transferable votes in the second count (most of the remaining 1,800 votes in that group had valid rankings for both Bond and Hoar, but not for the other two candidates). It has been suggested that these voters were confused as to which candidates would make it to the second count, but a far more likely explanation is that they simply wished to support the independent candidates only and didn’t care for either of the two major-party candidates. In fact, their behavior is functionally the same as that of voters in traditional runoff systems casting a blank or invalid ballot in the runoff election, after the candidates they originally supported were eliminated in the first round of voting. Moreover, Bond and Hoar first preference voters had the lowest proportion of bullet voting, at just under two out of seven ballots cast for them.

The overall distribution of bullet votes and preference votes in the CD-2 election closely resembles the 2016 and 2018 RCV referendum outcomes, and it would seem this is not entirely a coincidence: in towns with more than ten voters, there were moderately strong correlations between bullet voting in 2018 and opposition to RCV in 2016 (0.62), as well as between preference votes in 2018 and support for the new electoral system two years earlier (0.64); when the correlations were calculated on the basis of valid votes only, both stood at 0.63.

In conclusion, neither all GOP voters in CD-2 ranked Congressman Poliquin only (nearly a third cast a preference vote) nor did all Golden voters (or those backing independent candidates Bond and Hoar) rank other candidates – this was the case with almost three out of eight non-Poliquin voters. There was little evidence of voter confusion, and casting a preference vote or a bullet vote may have been indicative of ongoing support for RCV or opposition to it, respectively; if so, the election outcome did not point to growing opposition to the newly adopted electoral system. Just as important, these findings should leave no doubt that RCV is not a clear-cut partisan issue.

The gaming of Mexico’s PR disparity cap

One distinctive feature of Mexico’s 500-seat Chamber of Deputies’ mixed-member majoritarian system – under which 300 members are chosen by plurality voting in as many congressional districts, while the remaining 200 seats are filled by party-list proportional representation (initially determined on a nationwide basis) – is a provision which caps party representation at a maximum of eight percentage points above its national proportion of votes cast for parties entitled to participate in the distribution of PR mandates (in addition, no party may have a total number of Chamber seats in excess of 300 mandates). However, in recent years some parties running in electoral coalitions have successfully gamed the system to circumvent the limits imposed by this provision, effectively diluting its intended compensatory effects.

The eight percent disparity cap is implemented by determining the maximum number of Chamber seats each party may obtain; if a party exceeds this amount, its PR seat allocation is reduced so that its total number of plurality and list seats is equal to the capped seat total. For example, in the 1997 legislative election – generally regarded as Mexico’s first truly free and fair vote – the then-ruling Institutional Revolutionary Party (PRI) won 38% of the total vote and 39.98% of the “effective national vote” (“votación nacional efectiva” in Spanish), that is the total number of votes cast for parties entitled to take part in the allocation of PR seats. Therefore, PRI could obtain at most 47.98% (39.98% plus 8%) of the Chamber’s 500 seats, or 239 seats, disregarding fractions. Since PRI had won 165 of 300 plurality mandates in the election, and had been initially assigned 80 PR seats, for a total of 245 seats – six above the capped total – the party’s list mandates were reduced to 74 seats (239 minus 165); the remaining 126 PR mandates were then distributed among the other four qualifying parties.

Prior to 2008, Mexican voters could choose either a party running alone or a coalition, but not a specific party running within a coalition. Therefore, coalitions were treated as parties when it came to allocating Chamber seats and determining the eight percent cap. However, a 2008 electoral reform allowed voters to choose parties running as part of a coalition, and at the same time limited coalitions to plurality elections only. Since then, the distribution of Chamber PR seats has been carried out entirely on an individual party basis, even though coalitions have often continued to determine the outcome of plurality races; most importantly, the allocation of plurality seats among coalition partners has been determined on the basis of officially registered coalition agreements (“convenios de coalición” in Spanish). In due course, larger parties running in coalition with smaller allies discovered they could game the cited provision by assigning plurality seats in the coalition agreement to their junior partners, while these in turn nominated candidates who were actually members of the larger party. In this manner, the larger party artificially reduced its total number of seats, thus making it less likely that it would hit the eight percent cap during the allocation of PR list mandates.

Before 2018, PRI and its ally the Ecologist Green Party of Mexico (PVEM) gamed the system in the manner described, but the scope of their scheme was comparatively limited, not least because PVEM didn’t have a particularly large number of Chamber plurality seats to begin with. Moreover, in 2015 Mexico’s Federal Judiciary Electoral Tribunal (TEPJF) ruled that parties could nominate candidates from a different political party, provided the parties had a coalition agreement. On the other hand, the stratagem pursued in 2018 by the “Juntos Haremos Historia” (JHH; “Together We’ll Make History”) coalition of the National Regeneration Movement (MORENA), the Workers’ Party (PT) and the Social Encounter Party (PES) was anything but limited. For the Chamber of Deputies, the three parties ran together in 292 of Mexico’s 300 congressional districts, but in the coalition agreement 142 nominations were assigned to MORENA, and 75 each to PT and PES.

To be certain, it is not unusual for smaller parties like PT and PES to have a disproportionate share of single-member nominations in mixed-member majoritarian systems which allow party coalitions: in a nutshell, larger parties often bow to smaller parties’ demands, outrageous as they may be, if that is what it takes to avoid the risk of losing elections. That said, giving away half the Chamber’s single-member seat nominations to a couple of very small parties came across as both extreme and highly suspicious, all the more so considering that for the Mexican Senate plurality races, JHH nominated 49 candidates from MORENA, but only eight from PES and five from PT. However, unlike in the Chamber of Deputies, there is no eight percent cap in place for the distribution of Senate PR seats, and therefore MORENA gained nothing from giving away upper house plurality nominations to its much smaller allies.

JHH went on to score a landslide victory in the general election last July, securing an absolute majority for its presidential candidate Andrés Manuel López Obrador (better known by his initials AMLO), as well as a sizable plurality in the legislative election. In the Chamber of Deputies, final results show JHH won 220 of 300 plurality seats (including eight mandates won by MORENA running alone), with the following results for its constituent parties:

Party % (Votes) Seats % (Seats)
MORENA 37.2 106 35.3
PT 3.9 58 19.3
PES 2.4 56 18.7
JHH Total 43.5 220 73.3

The sole beneficiaries of the victorious coalition’s over-representation in the plurality component were PT and PES, as MORENA ended up slightly under-represented. Again, while it is not unusual for smaller parties within larger coalitions in mixed-member majoritarian systems to have a share of seats in excess of their percentage of the vote (even without considering the PR component), this was nonetheless a truly extreme outcome. By comparison, the Senate election had a more typical plurality outcome, as shown below:

Party % (Votes) Seats % (Seats)
MORENA 37.4 42 43.8
PT 3.8 5 5.2
PES 2.3 8 8.3
JHH Total 43.6 55 57.3

(JHH’s smaller majority of upper house plurality seats was due to the fact that unlike in the Chamber of Deputies, Senate plurality mandates are allocated on the basis of two seats for the winning ticket and one for the first runner-up in each one of Mexico’s thirty-two federal entities).

For the distribution of Chamber PR seats, MORENA received 41.34% of the effective vote, so it could have no more than 49.34% of the 500 Chamber seats, which translated to 246 seats. However, after the initial allocation of PR mandates MORENA had a total of 188 seats (106 plurality and 82 list), well below its corresponding maximum seat total. On the other hand, PT, with 4.36% of the effective vote, would have been entitled to nine list seats, but unexpectedly exceeded its 12.36% cap, or 61 seats due to the party’s large number of plurality victories; PES fell below the three percent valid vote minimum required to take part in the distribution of PR seats. Consequently, PT’s list seat total was reduced to three mandates, and the remaining 197 PR seats were distributed among the other six qualifying parties. In all, JHH won 308 of 500 Chamber seats, as detailed below:

Party FPTP PR Total % (Total)
MORENA 106 85 191 38.2
PT 58 3 61 12.2
PES 56 0 56 11.2
JHH Total 220 88 308 61.6

Mexico’s National Electoral Institute’s General Council Agreement INE/CG1181/2018 [PDF] details the official distribution of Chamber of Deputies PR list mandates in Mexico’s 2018 federal election, while Federal Elections in Mexico has nationwide- and federal entity-level results of elections in Mexico since 1997.

Although the eight percent cap deprived PT of just six seats, this left several of its leaders without a seat in the Chamber of Deputies, and the party went to court to have the result overturned. To that end, PT actually admitted some of its successful plurality candidates weren’t really party members after all, and sought a judicial review of JHH’s officially registered coalition agreement. However, the court rejected what it correctly perceived as a transparent attempt by PT to re-structure the previously agreed distribution of Chamber plurality nominations, in order to bypass the eight percent cap and increase its number of list mandates. In essence, TEPJF ruled JHH’s coalition agreement was a done deal which could no longer be altered after the election had been carried out with the agreement in place, and for good measure reaffirmed its earlier 2015 ruling that parties could nominate candidates from a different political party, provided the parties had a coalition agreement.

Just as important, TEPJF ruled that under the prevailing legal and constitutional arrangements, it was not possible to consider JHH’s coalition performance as if it were a single party for the purposes of determining over-representation, as it would run counter to the requirement such determination must be carried out on an individual party basis. Had Chamber seats been allocated among coalitions (and had all three major coalitions been in place in every congressional district, as was the case with the presidential election), JHH’s seat total would have been limited to 269 mandates – a significantly reduced yet nonetheless substantial majority.

TEPJF also confirmed that PT exceeded the eight percent cap by six seats (because 12.36% of 500 seats equals 61.8 seats, it was argued the party went above the cap by 5.2 seats (67 minus 61.8), which should have rounded down to five seats; however, this argument was rejected on the grounds that with 62 seats of 500 – 12.4% of the total – PT would have had a disparity gap of 8.04%, a figure just above the eight percent maximum).  The court ruled as well that JHH’s plurality victories could not be assigned to MORENA on account of the fact that the party contributed the vast majority of votes to that end.

(MORENA outpolled both PT and PES in every congressional district, and even if the party had run alone it would have secured a large majority of plurality seats, while PT and PES would have won none. However, in such hypothetical scenarios – which assume an identical distribution of votes among the parties contesting the 2018 federal election – MORENA’s Chamber of Deputies seat total would have been limited to 246 mandates by the eight percent cap, while PT would have received no more than 13 list mandates and PES would have had no seats, leaving MORENA and PT with a relatively slender joint majority in the Chamber.)

Nevertheless, TEPJF’s rulings on some of these controversies were not unanimous. Judge Felipe de la Mata Pizaña wrote a concurring opinion calling for the current implementation of the eight percent cap provision to be reconsidered for future elections, while Judge Reyes Rodríguez Mondragón issued an extensive dissenting opinion, in which he argued that the actual party affiliation of plurality winners should be taken into account for determining the eight percent cap during the distribution of PR seats. Notably, the dissent cites a number of political science scholarly sources, including both the Spanish-language edition of “Presidents and the Party System” (edited by S. Mainwaring and M.S. Shugart) and “Seats and Votes” by R. Taagepera and M.S. Shugart, even carrying out the calculations to determine the effective number of parties index for Mexico.

(For further information, please refer to TEPJF’s rulings on SUP-JDC-0429-2018; SUP-JDC-0438-2018SUP-JDC-0444-2018SUP-REC-0934-2018; and SUP-REC-0943-2018 [PDF].)

However, beyond the practical difficulties entailed by implementing this approach, it is not clear that it would have resulted in a significantly different distribution of seats. After Mexico’s newly elected legislators were sworn in just over three months ago, a large number of JHH’s 220 plurality deputies ostensibly elected as members of PT or PES joined MORENA’s parliamentary group, as shown below:

Party Elected Group Gain/Loss
MORENA 106 162 +56
PT 58 28 -30
PES 56 30 -26

Had the eight percent cap been calculated on the basis of parliamentary group affiliation figures, the initial distribution of PR list seats, which as previously noted granted nine mandates to PT and 82 to MORENA would have been definitive, as neither party would have reached its eight percent-capped seat total. Moreover – and quite ironically – JHH would have obtained an even larger Chamber majority of 311 seats (of which 244 seats would have gone to MORENA, 37 to PT and 30 to PES).

In conclusion, while PT and PES contributed very little in terms of votes to JHH’s sweeping victory in the 2018 federal election, the gaming of the eight percent disparity cap through the assignment of a disproportionately large number of plurality nominations to these parties allowed the coalition to obtain a much larger majority in the Chamber of Deputies than it could have otherwise attained. Even so, the triumphant coalition parties overplayed their hand, and the stratagem backfired on PT; this in turn led to a public disclosure of the scheme’s existence (already highly suspected, not least because it was largely absent in the Senate election, which has no disparity cap provisions), as part of an unsuccessful effort to have the unexpected adverse outcome reversed in court.

Even though a majority of Mexico’s Federal Judiciary Electoral Tribunal justices have reaffirmed the validity of electoral provisions which allow outcomes like these, it seems an obvious flaw in the design of the system that parties can run in alliances, but the caps on over-representation are calculated at the individual party level, as pointed out by Dr. Matthew Shugart himself on this blog shortly after the 2018 federal election took place. Moreover, the gaming of the eight percent disparity cap in the 2018 federal election effectively altered the nature of the Chamber of Deputies electoral system, causing it to function almost like a parallel system, in which the outcome of plurality races had very little impact in the distribution of party list seats. That may not appear to be cause for excessive concern in the here and now, given that JHH would have in all likelihood secured a majority of Chamber seats even if the coalition hadn’t gamed the eight percent disparity cap, but the issue could have wider ramifications with unpredictable consequences in the years to come.