Mitt Romney spent nearly six years making two straight bids for the presidency. But after coming up short both times, he finally threw in the towel for good early Wednesday, conceding that President Obama had beaten him and won re-election. "This election is over," Romney told supporters, "but our principles endure." Moving forward, where and how will Romney apply those principles, not to mention his mix of business and policy experience, now that his White House dreams have been dashed? Here, five theories on what the defeated GOP presidential candidate might do now:

1. He should become a party elder
Romney still has a bright future in the Republican Party, Newt Gingrich tells CNN. There's a "major role" for him to play in guiding the GOP and spelling out the party's agenda over the next four years. "Clearly he is a major figure in the party." But when 2016 rolls around and it's time for the GOP to take another crack at the White House, that won't be a job for Romney, but the "next generation" of GOP standard bearers.

2. He should rejuvenate the conservative movement
"Mitt Romney's time as a frontline politician is over," says Pascal-Emmanuel Gobry at Forbes. "He now has a legacy to build. At 65 and with a healthy lifestyle, he is still in his prime." Perhaps he can "fund and run a foundation dedicated to fostering and researching new, innovative right-of-center policy ideas." That way he might "ultimately be remembered as the man who breathed new intellectual life into the movement, not the one who led it to defeat."

3. He should take some time for himself
Even those close to Romney have no idea, really, what he'll do next, says Scott Conroy at Real Clear Politics. But you'd think that he'll relish having more time with his family. Aides see him spending more time with his grandkids, and maybe working on business ventures with his sons.

4. He should write a book
If he decides he wants to write a book about his months touring the country, he's got plenty of notebooks he filled during quiet moments on the campaign trail, according to one longtime aide. "He hasn't kept a diary per se, but he's always taken notes," the aide said. "On the plane, at least, it's always seemed like he's very reflective of what he's been doing."

5. He should wait before making new plans
"Anytime you go for a big job, you start to imagine having it, doing it," says Margaret Heffernan at CBS News. "When those images are taken away, you grieve. Grief is a bad state in which to make decisions." So the first thing Romney should do is... nothing. He should get insights from others into what he did right, and wrong. Romney needs to "take stock and be prepared to listen to hard truth." Then he needs to get back to work. He doesn't need the money, but "smart, healthy people want to work and should work: The world needs their contribution." Defeat can be catalytic. "Great leaders always cite their mistakes and failures as moments of growth." Whatever Romney does next, he shouldn't "let a defeat go to waste."