Monday night, ahead of the Michigan primary, the Rick Santorum campaign unleashed a last-ditch robo-call reminding voters of Mitt Romney’s staunch opposition to the auto-industry bailout. This, argues Romney, was a “dirty trick” to lure Michigan’s Democrats to the Santorum side. “It’s outrageous to see Rick Santorum team up with the Obama people and go out after union labor in Detroit and get them to vote against me,” Romney said Tuesday, insisting that “we don’t want Democrats deciding who our nominee is going to be.” The Santorum call said, “Romney supported the bailouts for his Wall Street billionaire buddies but opposed the auto bailouts. That was a slap in the face to every Michigan worker, and we’re not going to let Romney get away with it.” Romney may denounce Santorum's lastest effort to get Democrats involved in the Republican primary, but it has not been forgotten that Romney himself voted in the 1992 Democratic party in an effort to nominate his opposing party's weakest candidate to go up against incumbent President George H.W. Bush.