The fragmentation of the US Democratic Party’s field of presidential pre-candidates exaggerates the weakness–real though it is–of the clear front-runner, Joe Biden.
It is noteworthy that even with so many candidates and different methodologies, the two trackers agree on the order. The only really substantial difference between them is in the estimate for Bloomberg. Not shown here, the two trackers also agree in the order of the next three: Yang, Klobuchar, and Booker. After that they diverge on the farther trailing candidates. (Economist has both Gabbard and Steyer at 1% but lists her ahead of him; perhaps we could say they agree on the order of the top ten.)
In the Economist tracker, the full list of all candidates who are given a vote percentage includes five listed as “<1%” (trailing two estimated at 1%). If we assumed all these five averaged 0.5% (which is probably too high) we still get to only 88.5% as a “total”. So that leaves too much for the thirteen who were running but have dropped out; the tracker does not report a percentage undecided. If we take Biden’s percentage over all those with at least 1%, he is just over 30%. Still pretty weak for a front-runner. But the one in second place, Sanders, would rise only to just under 20%. That’s a large gap.
Applying the same exercise to the FiveThirtyEight percentages–which have six candidates over 1%–we get a “total” of 86.3% and the top two at 31.6% and 20.6%.
The Democratic Party obviously does not use a nationwide two-round majority rule. But if it did, where would a top two 30–20 finish rank? How likely would it be that the second place candidate would win the runoff? I looked at this question in 2016; the graph at that post shows rather few real-world presidential contests with approximately 30–20 for the top two. But if one were to draw a line on the graph marking the region in which the gap is ten percentage points or more, no second-candidate comeback shows up with this large a gap until the leading candidate is around 35% (Austria 2016, the case that prompted the post). That is, even with a first-round candidate as weak as a third of the vote or less, comebacks occur only when the two are rather closer than Biden and Sanders are at this point. And this is, of course, before one even considers ideological placement of the candidates.
What I am getting at, in case it is not obvious, is that it is hard to imagine Biden not being the winner were there a hypothetical direct two-round primary–and even if the field stayed this fragmented up till the first round (which is itself unlikely). Perhaps Warren’s chances increase slightly if this nationwide primary were run under the alternative vote. She might pick up enough from eliminated candidates to surpass Sanders in the final two when calculated this way. It still seems a stretch that she could end up with a majority after reallocation of presences.
Now, let’s try a different hypothetical. The primary actually uses proportional representation to allocate delegates. Sort of. There is a 15% threshold, and the rules consist of a mix of statewide delegate allocation and allocation in congressional districts using varying district magnitude. If it were a single-shot affair rather than sequential across states and regions, only three candidates look like they would get any delegates (generously granting Warren what she needs to get over 15% in the FiveThirtyEight tracker or allowing for regional variance even if she stayed at 14.7%). In this scenario, Biden has 44% or 45% of the above-threshold vote. That might just be enough to win a majority of elected delegates or close to it, given a medium district magnitude on average. It would certainly put him close.
(There are 3,836 “pledged” delegates; 435 congressional districts plus separate statewide districts for the states that have more than one congressional district, DC, and various territories means ~480 districts, so an average magnitude of about 8.)
None of this is to say Biden can’t be caught by someone. And in the real and strange world, Iowa and then New Hampshire get to go before anyone else. According to FiveThirtyEight, Biden is in a tight three-way fight in their Iowa estimate, with Buttigieg still clinging to a slight lead over Biden and then Sanders (19.7–19.1–18.3), with Warren at just 13.4%. The New Hampshire estimate is similar, only with Sanders the one clinging to a narrow lead over Biden and Buttigieg (18.0–17.3–15.6) and Warren at 13.9%. (Gasp–the fifth place candidate is Tulsi Gabbard, on 4.9%.)
The odd (I am being kind) procedure the party uses in the real world could still produce a surprise, if Biden fails to get a plurality in either Iowa or New Hampshire, and if the pre-candidate (or two or more) beating him were to surge nationally afterwards. It looks unlikely to me. I think Biden has it, barring an occurrence of something even stranger than the method by which the party selects its nominee.