To be fair Obama and Edwards weren't on the ballot I imagine Obama probably would have won.
It would have been a toss up between Obama and Edwards to win Michigan. Edwards' helping everyone out blah blah blah would have resonated well with people in Michigan, I'd think.
But considering neither were even on the ballot (and none of them campaigned in Michigan) that's not a good sign for Clinton if that many showed up just to vote against her.