He even took a gentle swipe at the news media, mocking what he said were inaccurate articles suggesting that his oldest son, Tagg, had staged an intervention to fix a tottering campaign and was playing a heavy role in shaping political strategy.

“He will be sifting through this for quite a while,” said Kirk Jowers, a Romney friend. “The question is when the sifting takes a couple of hours a day instead of being all consuming.”

Even his own aides said it was hard to know precisely how Mr. Romney, an unsparing self-critic, would respond to a loss that had such a personal dimension. It was his second run for the White House and he had believed, until the very end, that he was ever so close to fulfilling the dream of his father, George, whose own presidential aspirations fell short in 1968.

Few of them can imagine him following the path of, say, Bob Dole, who traded in the title of Republican nominee to become a lobbyist and a pitchman for Viagra. Or Al Gore, who graciously accepted loss in public, then descended into a private slump, growing a beard and putting on weight before slowly finding his passion in environmental advocacy that won him a Nobel Peace Prize.

“The only door that is closed to Mitt Romney for the remainder of his life is being president of the United States,” said Steve Schmidt, a campaign adviser to Senator John McCain in 2008. “He can do whatever else he wants to do.”

He had a warning, though: “Losing a presidential campaign is something you never get over. The question is whether you can move forward without bitterness or rancor.”