They hold a ‘jungle primary” in November in lieu of a general election, with the two top vote-getters advancing to a runoff in December unless one of them somehow pulls a clear majority.
No one thinks Landrieu is getting 51 percent on the first vote, so even if Palin drives a chunk of tea partiers away from Cassidy and towards Maness, Cassidy’s still going to be in the runoff with Landrieu. Palin might even endorse him at that point in the name of party unity, just as she has Pat Roberts in Kansas.
Cassidy is a liberal Republican. Because there is no party primary, this is the only way to remind him that he is dependent on the conservative vote if he wants to win. So he needs to tack right and stay more on that course.