From the blog "Red State":
It's all in DeVos' hands now. He can self finance, and has a core following, particular among school choice supporters and some social conservatives. DeVos's wife Betsy, was also the state GOP chair during much of the 90's, and from 2003-2004, so there is an organization base to start with.
IMO, DeVos already has most of the "social vote" wrapped up to begin with, so he needs to (and is) running on the economy. He shouldn't run from his stands on issues(even vouchers, smartly saying that the people had their say on it), but the big issue here is the economy. The recovery has skipped Michigan. This race is certainly winnable, for that reason alone.
It'll be interesting to see if this commentator gets it right and DeVos stays away from vouchers with his campaign message. If he does, though, he certainly won't stay away from it if he wins.