According to the pollsters and pundits, Mitt Romney should win tomorrow's Arizona primary handily, while the Michigan primary looks like a tossup.
What happens will set the stage for the caucuses in Washington Sunday, and Super Tuesday next week. Romney is expected to win Massachusetts and Vermont, and gets a gimme in Virginia, where only he and Ron Paul are on the ballot. He may also win the caucuses in Idaho and North Dakota, and the district conventions in Alaska.
But he appears to be trailing Rick Santorum in Washington and Ohio, and is well behind him in Tennessee and Oklahoma, while Newt Gingrich leads Santorum in Georgia.
It seems to me that Gingrich is the big question mark. The recent trajectory has been a steady drop in support for Newt, most of which goes to Santorum -- but he's still maintaining enough of a base to matter in a couple of ways.
First, the 10% or so he's projected to get in Michigan, and roughly 20% in Arizona and Ohio, could be enough to deprive Santorum of victories or close margins (and delegates).
Second, if Gingrich disappeared, Santorum could probably put the South in his back pocket -- not just on Super Tuesday, but in upcoming votes in Alabama, Mississippi and elsewhere. That's a lot of delegates and victories, while still leaving him free to concentrate his time and resources on states like Ohio, Illinois, and Wisconsin.
It's unlikely Gingrich will actually drop out before Georgia votes on March 3. The question until then is whether people who say they intend to vote for him decide to switch to help decide between the 'big two.'
You would think that quite a few of those 10% in Michigan would do that, as they see how close the polls put the Romney-Santorum contest in that state. And, if that helps Santorum win Michigan, or come very close, that should encourage more people in Ohio and even Georgia to do the same. Super Tuesday could turn into a very big day for Santorum.
On the other hand, if Romney pulls out a sizable win in Michigan -- say, 8 percentage points or more -- that could take a lot of wind out of Santorum's sails, making Gingrich voters more likely to stick with their choice.