A package of political reforms is wending its way through the Colombian congress (yes, again). Among the provisions is one that would grant an automatic seat in the Senate to the runner-up in the presidential election.
I am aware of one other country that has (had?) such a provision: Nicaragua under its 1987 constitution. Are there others that readers are aware of?
The appeal of this sort of measure might stem from “parliamentary envy”: In parliamentary systems, it is almost guaranteed that the prime ministerial candidates of the main losing parties (as well as the leaders of other parties) will have seats in the legislature. On the other hand, what if a defeated party replaces its leader, as is actually quite common in parliamentary systems?* The new leader typically also has a seat in parliament, but under the “defeated presidential candidate” provision, a change in leadership would not change who represents the party as its “opposition leader”. This seems less than helpful to establishing “opposition guarantees” (the name of the constitutional amendment bill in Colombia).
Basically, it seems to me that members of an elected legislative body should have to win seats themselves (via whatever candidate-selection processes and electoral system apply to the body), rather than be given one via the outcome of the executive election. That is, the measure strikes me as a poor substitute for strengthening parties such that the opposition to the president has a platform in the legislature. Of course, Colombia has tried various such measures since its major constitutional process of 1991 (and earlier). And they keep coming up short.
The Colombian bill goes one step farther: the running mate of the runner-up would get a seat in the House of Representatives. Because, after all, there are few things more valuable to national discourse than defeated vice-presidential candidates.
* Very recent example: the leaders of the Labour and Liberal Democratic parties resigned their positions (though will remain MPs) immediately after the British election.