I don't know how anyone could consider Michigan to have been a legitimate election: Obama wasn't even on the ballot.
Because he willingly took his name off of course.
Because it was a non-binding "beauty contest" not recognized as allocating delegates by the DNC.
That's fine, but the DNC doesn't run Michigan elections. It was a perfectly legitimate election--internal to Michigan--for determining delegates to the Michigan caucuses. Michigan let Obama on the ballot and never told him he had to take his name off.