But again...the original point to which I responded is the claim that one possible outcome of the Bush v. Gore dustup is that Cheney could have become president. Not true under any circumstances except one. If something happens so a president-elect could not be inaugurated on Jan. 20, the vice president-elect becomes acting president.
I think most people would say "yes," that the concession was premature and that the law would recognize the vote count, not the concession. This is backed up by examples of retracted concessions, meaning that a concession is not a permanent decision.
Add to this the Electoral College. If Bush were to concede and Gore still failed to win 270 Electoral Votes (because Florida still voted and certified for Bush), then he does not win just because Bush conceded. He would have failed to win the majority in the Electoral College, and the House of Representatives would choose the President.
Where the 20th amendment would apply is if the winning candidate declines the office (which is not the same thing as conceding the election). If Bush were to decline to serve after winning the election, then Cheney would become acting President until a permanent President is chosen.
The actual vote is the law, not the candidate's words.
-PJ