The most important number coming out of the Iowa caucuses is 75.7. That's the percentage of Republican voters who chose a candidate NOT named Donald Trump.
The question now is whether the Rational Right, the sensible wing of the Republican Party, can take advantage of Trump's vulnerability. Can they unite behind a solid alternative to Trump and Ted Cruz, who won Iowa but is even more unreasonable and unelectable than The Donald?
The obvious option is Sen. Marco Rubio of Florida, who finished a strong third in Iowa and, on paper at least, represents the biggest threat to the Democrats: a young, appealing, Spanish-speaking son of Cuban immigrants with a vibrant story from a vital state.
Rubio has yet to fulfill that sizable potential, but Iowa showed he might be starting to gain traction. He won almost a third of late-deciding caucusgoers.
Still, Rubio faces a tough time in uniting the Rational Right. John Kasich, Chris Christie and Jeb Bush are all focusing on New Hampshire and dreaming that they can still emerge as the Non-Trump. Until the field clears, Rubio won't have a clean shot at Trump or Cruz -- let alone Hillary Clinton.
But the Democratic results in Iowa should give the Rational Right renewed incentive to unify. Clinton almost lost to Bernie Sanders, a 74-year-old socialist, and entrance polls revealed her core weaknesses. She is beatable -- as long as the Republicans don't self-destruct.
Among voters who picked trustworthiness as an important trait in a candidate, 83 percent backed Sanders. Iowans looking for someone who "cares about voters like me" went 3 to 1 for Bernie.
Questions about her honesty and empathy have plagued Clinton her entire career, and they have not gone away. That's why the lingering email mess is so damaging. It plays into an existing storyline about both Clintons: They always play the angles and parse the truth.
After Iowa, Trump is not invincible or inevitable. But Clinton isn't, either. So what's next?
Writing for the Cook Political Report, Amy Walter smartly points out that Trump's brand of bombast can backfire. "Trump brings out as many people fearful of his candidacy as those who are attracted to it," she writes.
And after flirting with a series of novices for the last six months -- add Ben Carson and Carly Fiorina to the list -- many Iowa Republicans were ready to get serious. They divided evenly between wanting a candidate with "experience in politics" and one who was "outside the establishment."
Of those who valued experience, Rubio came in first, while Trump disappeared, polling only 3 percent. And the scrutiny of his record -- or lack of one -- will only get more intense.
Katie Packer, a former Mitt Romney aide who organized an anti-Trump super PAC, told Politico: "The big takeaway is that two weeks ago, everybody said, 'There is nothing you can do to stop Trump.' We showed a spotlight on his record and his comments."
Here's a bigger question. Trump has built his whole campaign on a simple idea: "I'm a winner and everyone else is a loser." So what happens when he fails? What does he have to fall back on?
In Iowa, 42 percent of Republican caucusgoers said they wanted a candidate who "shared their values." Of those "value voters," only 5 percent picked Trump, and for good reason: He has no values. Or to be precise, he only has one: his own celebrity.
The "bandwagon effect" is well documented in political science; voters like to back a winner. And as Brendan Nyhan wrote recently in The New York Times, "Trump's initial success may have helped attract more support, creating a positive feedback dynamic that helped fuel his monthslong ascent in the polls."
But once he stumbles, that dynamic could turn negative. "Trump's supporters may shift their support to another candidate," Nyhan writes, while others "could become discouraged and fail to vote at all."
That's why the tribunes of the Rational Right are breathing a bit easier after Iowa, with David Brooks writing in the Times that "the amazing surge for Marco Rubio shows that the Republican electorate has not gone collectively insane."
True, but remember the old adage: "You can't beat somebody with nobody." If the grown-ups in the Republican Party want to block Trump and Cruz -- and have a chance at beating Clinton -- they have to coalesce around a credible challenger.
"Nobody" is not good enough.