This is a good point. If Obama is running unopposed, then the Dems have nothing to lose by voting Ron Paul in the (R) primary. Dems who 'lean toward Paul' get a chance to hear them both in debates and make a final decision; Dems who like Ron Paul but didn't want to switch party-lines before can vote for Paul and not feel like they're traitors to their party; and Dems who believe "he'll never win" but are afraid a different Rep *might* can vote just 'to sink' the Rep's chances.