Minnesota’s Senate race, between Republican incumbent Norm Coleman and challenger Democrat Al Franken, is heating up. Taking a move from his successful 2002 playbook, Coleman has vowed to pull all of his negative ads. And while Coleman and Franken battle it out, there isn’t much doubt that the Independence Party’s Dean Barkley will act as a spoiler in the race. The question is, Who will he spoil it for? Guest: Bob Collins, Minnesota Public Radio