Josh Putnam notes the Michigan Republican primary will be fought, not statewide, but on the congressional district level.

“Strategically, if you’re Mitt Romney or a Romney-aligned super PAC, you focus on the districts in and around the Detroit area and perhaps cede the rest of the state to Santorum. And if you’re the Santorum camp you try and gobble up as much of the remainder as you can and hope to crack into those Detroit areas.”

“The bottom line is that barring an overwhelming victory for one candidate in Michigan, the delegate margin is very likely to be close coming out of the Great Lakes state on February 28.”
Taegan Goddard’s Political Wire