Romney seems to be winning support from the rest of the field by promoting himself rather than attacking his main competition. He has spent a lot of time in Michigan emphasizing his ties to the state (ineffectually, according to PPP, with only 29% buying that argument), and making the case that his executive experience and turnaround capabilities are what is needed in this election. Even his opposition to the automaker bailouts isn’t hurting Romney (only 27% think that’s a negative, and 35% don’t care about it at all); voters seem to be rethinking Romney on the basis of his approach to the economy.
At this point, a flailing Gingrich is sustaining Romney:
When Newt Gingrich gets removed from the equation, Santorum leads by nine points, 42/33, which means that Romney has gotten about all of the Gingrich support he’s going to get in Michigan, and the rest would tilt to Santorum.
Doug Mataconis, who anticipates a close finish in Michigan, looks ahead to Wednesday's debate:
[A] significant part of the debate is likely to focus on social issues and the statements that Santorum has made on everything from contraception to women in the military to same-sex marriage. How that plays out in the context of a Republican nomination fight, though, is unclear. You’re not going to hear Romney, or Gingirch, or even Paul argue that Rick Santorum is too socially conservative, because they’re not going to risk pissing off the same people that Santorum is appealing to. What could happen, though, is that Santorum’s positions on these issues will have a negative impact on independent voters (Michigan has an open primary) and Republican women to such an extent that they start lining up behind Romney to stop him.