Things have changed considerably in Michigan over the last 6 or 8 years. Its also important to note that the 04 race wasn’t exactly a blowout for Kerry in Michigan (something like 4 or 5 percent). 08 was different because it was the “historic” election of a black man.
Now our voter ID laws are firmly in place. We have one of the best secretaries of state in the nation and she is backed up by a good attorney general. Both of them were targets of fraud and have zero tolerance for it.
As someone else pointed out upthread, unions in Michigan are in disarray now as well. There are divisions between public and private sector unions with divisions within both. The union conservatives are openly supporting Romney and right to work laws and factions within the SEIU are now suing each other.