A friend of mine asks:
Imagine I'm [a Candidate X] supporter, in Pennsylvania, and I got to the polling place at 7 p.m. to find a six-hour line. At midnight, I am still waiting to vote when I hear on the radio that [Candidate Y] has conceded. Does that mean I can finally go home? Or should I stay and vote, on the theory that the concession has no meaning, legally, and the votes will still have to be counted?
An interesting question -- I suspect likely purely academic, but, hey, this is an academic blog. Here's my tentative thinking:
1. To begin with, there's no caselaw specifically on this point, so the answer may well not be entirely clear. (I'd love to hear, by the way, if there's some caselaw for other kinds of elections, though that would be at most persuasive, and not binding, as to the Presidential election.)
2. In many situations, a person may be legally bound to a concession he made -- for instance, a withdrawal from a particular contracting process, or a promise (even short of a binding contract) to do something -- especially when others have relied on this concession; a common term for this is "estoppel." But this needn't always be dispositive, especially when the rights of other parties (here, the voters and electors) are involved. Nor is this a normal sort of business transaction, where standard legal rules of estoppel may routinely apply.
To illustrate this, let's say that Candidate Y concedes, believing that he has lost, but it turns out that he has a majority of the votes cast ("majority" being defined as "majority according to the popular vote as reflected in the likely electoral vote"), and that he might or might not have a majority of the votes that would have been cast had he not conceded. Treating his concession as binding affects not just his interests, but the interests of the voters who actually voted, the majority of whom actually does not want his rival as President (though of course we should remember that the majority result might have been different were it not for his concession). It also affects the interests of the Electoral College and the House. Even though Candidate Y has the constitutional power to refuse the office, and even if such a refusal once made and relied on is treated as binding, he has no constitutional power to just turn the office over to his rival, or to undo the election of his electoral college slate, or to instruct his electors to vote for his rival.
3. As item 2 has foreshadowed, there are at least four possible constitutional players in this decision: The Electoral College, the Congress that counts the Electoral College votes (see the 12th Amendment for the roles of both, and the 20th Amendment for a possible extra role for Congress), the state legislatures that direct the appointment of the electors (see Article II, section 1), and the courts (see Bush v. Gore). There really is no precedent, as I suggested in item 1, that makes clear what any of these players would do.
My sense is that, whatever the courts' power to affect the continued counting of the vote, once the vote is counted and electors are chosen, the courts have no authority to interfere with the electors' and Congress's decision -- those decisions are constitutionally left to the electors and to Congress. If the law in some states explicitly leaves to the state legislatures the appointment of electors in cases like this, then the state legislatures can make a decision (without supervision by the courts, I believe); but I doubt that any state legislatures actually have such laws, and I doubt that they can just make them up as they go along.
So the main players, I assume, will be the electors. Though the electors in some states, I believe, are required by state law to abide by the election results in that state, I don't think such a command is legally enforceable; so if the electors decide to change their votes, they would be entitled to. Then it will be for Congress to count the votes, again, I think, without court supervision, and in the process decide whether the electors should be considered duly elected, or whether Candidate Y, if he has the majority of the electoral votes, nonetheless "failed to qualify" by virtue of his concession. I don't think there'd be much by way of legal standards to guide either group. Much would depend on the electors, the Representatives, and the Senators' sense of justice, of what is best for the country, and of what the public wants or should want -- and naturally all this will be inevitably affected by the players' political affiliations.
4. In any event, if candidate Y does concede prematurely, thus affect the behavior of enough voters that the premature concession might have made a difference, and then continues to fight the matter -- creating a constitutional crisis that was caused by his own error -- that strikes me as quite bad behavior on his part. (Note that this is not the same as Vice-President Gore's actions in Bush v. Gore, since Gore's concession did not affect the casting of any votes, and thus didn't cause the sort of uncertainty that the hypothetical posits.) I would hope that the electors and Congressmen would be influenced by this in deciding against him, to the extent that they feel their constitutional role entitles them to consider this (and I think it should, unless they conclude that the constitutional text is somehow binding on the question).
And I would hope that candidate Y would avoid creating such a situation, either by delaying his concession, or by sticking by it, and instructing his supporters (among the electors and among the Congressmen) to treat him as no longer being a candidate. If the consequence is the frustration of the possible will of slightly more than 50% of the voters, and the enforcement of the will of slightly less than 50% of the voters (which we can't even be sure of, given the hypothesis that the concession might have changed the outcome), it seems to me that the avoidance of a serious constitutional crisis is a national benefit that more than outweighs the national cost of this consequence.