Mitt Romney is feeling confident. The former governor is boasting that he'll take the hard-fought Michigan primary today, the AP reports—but it's going to be a nail-biter. Eleventh-hour polls show Romney and Rick Santorum neck-and-neck in the state. Nate Silver is estimating Romney will best Santorum by the narrowest of margins—38.7% to 38%—but gives him a 55% chance of winning the state, to Santorum's 45%. Public Policy Polling, however, declares advantage Santorum, 38% to 37%, with Ron Paul and Newt Gingrich at a distant 14% and 9%, respectively. "It's always good to be cautious with one night poll numbers, but momentum seems to be swinging in Santorum's direction," notes PPP, which says Romney led in Sunday interviews, but Santorum grabbed a 5-point advantage among people polled on Monday.
Things are far clearer in Arizona, where Romney is poised for a cakewalk. He leads Santorum 43% to 26%, PPP finds, while Gingrich stands at 18%, and Paul at 11%. Romney is winning even among the groups he has struggled with, with leads among Tea Partiers, "very conservative" voters, and evangelicals. Indeed, with so many early votes cast in Romney's favor, you could say he has won already, the pollster notes. (Read more Mitt Romney stories.)