As the results come in, keep a few things in mind.
In some communities, the absentee voter ballots are counted last and come in late. Mitt Romney has been leading in the polls among seniors, so the AV vote should favor him substantially. 
I say substantially because it appears the turnout in some parts of the state is bordering on pathetic, and we could see AVs comprising 35 percent or 45 percent of the total votes cast.
A growing trend in Michigan is that AVs make up an extraordinary percentage of ballots cast. Romney’s edge is with the people who remember his dad, and the Oakland County senior women who were raised in a very different Republican Party who want nothing to do with Rick Santorum’s “culture warrior” approach.

Turnout and get-out-the-vote may be the key to winning this contest.
Across Michigan (and certainly in Macomb), the Romney people are certainly far more organized than the Santorum troops. Santorum is largely leaning on local tea party groups to do all the work. No real grassroots organization to speak of.
 
Santorum clearly has an enthusiasm gap in his favor, but none of these guys are real popular (almost no endorsements made by any GOP elected officials — past or present — in Macomb). I give the edge to organization and the electability factor.
One other thing: remember that Michigan is awarding delegates by congressional district (the new district lines) – two delegates for each district won by a candidate, plus two delegates for the statewide winner. Let’s hope the broadcast and cable networks keep that in mind.