His initial plan: spend time with his family. He has five sons and 18 grandchildren, with a 19th on the way.
"I don't look at postelection to be a time of regrouping. Instead it's a time of forward focus," Romney told reporters aboard his plane Tuesday evening as he returned to Boston after the final campaign stop of his political career. "I have, of course, a family and life important to me, win or lose."
The most visible member of that family — wife Ann Romney — says neither she nor her husband will seek political office again.
"Absolutely he will not run again," she told the hosts of ABC's "The View" in October when asked if a loss would mean the end of Romney's political career. "Nor will I."
Romney's senior advisers refused to speculate publicly about what might be next for their longtime boss. There was a general consensus, however: The 65-year-old Romney is unlikely to retire altogether. But following his defeat, his future role in a divided Republican Party is unclear.
"He's not a guy who's going to stay still, right. He's not a guy that's just going to hit a beach, play a lot of golf. He'll do something," said Russ Schriefer, one of Romney's top strategists.
The Republican presidential nominee spent most of his career in private business. He's run for office four times, and lost all but his bid for Massachusetts governor in 2002. That year, he ran as a moderate Republican who supported abortion rights and struck a conciliatory tone on gay rights and climate change. He also ran for the Senate.
After he decided to run for president, some of those positions changed. In his two presidential campaigns, he ran as an opponent of abortion, advocated amending the Constitution to ban gay marriage and described himself as "severely conservative."
But the Republican Party's most passionate voters never fully embraced him. Romney struggled through a long and nasty primary, losing state contests to former House Speaker Newt Gingrich and former Pennsylvania Sen. Rick Santorum, both of whom had long been sitting on their party's sidelines.
It wasn't immediately clear if Romney will seek an ongoing role in a Republican Party that's embarking upon a period of soul-searching. With a successful career in the private sector, he could secure a position in private business, though he is worth millions and hasn't worked a job with a regular paycheque in more than a decade. Those close to Romney also suggest he could purse philanthropic opportunities or even play a role in the Olympics after having led the 2002 Winter Games.
Frustrated conservatives may make a full return to politics by Romney, even in a supporting role, difficult on the national stage.
"What was presented as discipline by the Romney campaign by staying on one message, the economy, was a strategic error," said Marjorie Dannenfelser, president of the anti-abortion group Susan B. Anthony List. She argued that Romney handed Obama a victory by failing to focus on a socially conservative agenda.
On the flip side, other party leaders are insisting his loss means the GOP needs to reject some of the harsh rhetoric Romney embraced on issues important to women and Hispanics. "The country is changing, and the people our party appeals to is a static group," said Republican strategist Mike Murphy.
Romney won the nomination over the course of years. While he formally ended his first presidential bid in 2008 after losing the nomination to John McCain, he went on to build a network of political support by turning immediately to raising money for candidates and officeholders in the states he would need to carry him to the 2012 nomination.
He formally launched his second presidential bid in June 2011. Many members of his senior staff were already living in Boston by that point, uprooting lives in Washington or New York to commit to Romney's campaign.
On Tuesday, that all ended. By the end, running mate Paul Ryan said Romney was "running on fumes."
As the returns rolled in and state after state was called for Obama, Romney tuned out entirely at times.
"At one point tonight, he just turned off the TV and just played with the grandkids," said longtime aide Eric Fehrnstrom, standing in the ballroom after Romney's concession speech.
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