It's a big election night for the Republicans. Michigan results will start coming in at 5 pm, though some polls in the state don't close until 6. Arizona polls close at 7 pm PST. Here's what to expect:
Romney's got Arizona wrapped up, and all eyes are now on Romney's home state of Michigan. Santorum was in the lead in Michigan polls until last week, when Romney pulled ahead. But according to a Public Policy Polling poll last night, they've pulled into a dead heat, with Santorum gaining a slight edge in momentum. Turns out, the Republican primary in Michigan may come down to Michigan Democrats. Santorum has been robocalling Democrats and urging them to vote for him—Michigan is an open primary—which Mitt Romney is calling a "terrible dirty trick." Santorum says that's bullshit, but not in so many words. And of course, as Dan told you yesterday, Daily Kos is trying to throw the race for Santorum, too.
So here's the deal: A Romney win in Michigan doesn't change anything, but a Santorum win continues to chip away at Romney's inevitability argument. If Romney loses Michigan and the Washington caucuses this Saturday, he's on weak footing for next week's Super Tuesday. And as Mark Halperin said this morning, if Romney gets "blown out" on Super Tuesday, the Republican establishment is going to have to start looking for another candidate.