Later tonight -- or, if worst comes to worst, in the next few days -- either Mitt Romney or Barack Obama will be forced to take the stage and deliver a speech conceding the election to his rival. It's a painful task: After more than a year of making the case that he spoke for the people, one candidate must humbly admit that the people have spoken -- and chose the other guy. Here are six examples of candidates who utterly failed to step gracefully away from the limelight.

Richard Nixon, 1962

It's hard to imagine how Richard Nixon returned to political prominence from the nadir of what he wrongly declared his "last press conference," after losing the 1962 California governor's race. Nixon's remarks, a bravura display of self-pity, have widely been derided as the worst concession speech in U.S. history: "I leave you gentlemen now and you will write it," he told the assembled reporters. "Just think how much you're going to be missing. You won't have Nixon to kick around any more."...