8:35p.m.: Santorum wins Tennessee, NBC projects. Which means "Romney can't win the South," Chris Matthews says -- though few think most of the region will be up for grabs this election.
8:06p.m.: Fox projects Santorum wins Oklahoma.
8:00p.m.: NBC calls Massachusetts for Romney. Oklahoma is too close to call, though Santorum is in the lead. Tennessee and Ohio are too close to call.
7:47p.m.: Fox shows how close the returns are in Ohio.
7:45p.m.: Paul is speaking to his adoring supporters. On Fox News, Shep Smith tries to figure out what his deal is.
7:32p.m.: Romney won working women in Ohio with 45 percent. But! Santorum won married women. Santorum won everyone else with 39 percent. A few supporters are trickling into Santorum's speech area:
7:30p.m.: Polls have closed in Ohio; exit polls show Romney is ahead.
7:27p.m.: Fox News' Shep Smith almost declares Romney went "three for three tonight." Oops, two for three. But if Gingrich only wins one state, his homestate, does it really count?
7:23p.m.: Romney fans begin to file in to the victory speech area:
7:22p.m.: Ohio closes in a couple minutes. News can't be great if Santorum's campaign is already promising to go to the convention.
7:16p.m.: Romney wins Virginia, NBC says. Exit polls show Paul won those under 44, and those making less than $50,000 a year, barely, and unmarried men. Romney wins everything else.
7:15p.m.: It looks like both Paul and Santorum broke the 20 percent threshold to get delegates in Vermont, so Romney won't be able to take them all, The New York Times' Nate Silver points out.
7:10p.m.: You expect voters to convince themselves that the candidate they're backing has the best chance to beat President Obama. That's the majority view among supporters of each candidate. But! Romney had the smallest percentage of people who think he's the best one to beat Obama actually vote for him, 55 percent. By contrast, 93 percent of the people who thought Gingrich was the best one to beat Obama actually voted for Newt. From the CNN poll:
7:04p.m.: Looking at Georgia exit polls: Newt had a bit of a gender gap, getting 47 percent of men and 43 percent of women. Gingrich tied Ron Paul among young folks with 27 percent of the vote each.
Gingrich won all other ages, and he won all income groups except post-grads -- those are Romney's people. He won them with 40 percent to Gingrich's 32 percent. Gingrich won all income groups except those making over $200,000 a year -- again, those are Romney's people.
Gingrich is Catholic, but Romney won Catholic voters, 43 to 35 percent.
Santorum won a few groups in Georgia: those who think abortion should always be illegal, and those who think a strong moral character is the most important quality in a candidate.
7:00p.m.: Newt wins Georgia. "Georgia very much on our minds right now" -- Wolf Blitzer, poet. Romney likely wins Vermont, but it's "too early to call."