. . . but it’s not because I have any special ability to draw a primary challenger out of thin air.

It’s because there are credible challengers sitting on the sidelines, waiting to jump in if Lincoln does filibuster health care. And if I know it, she knows it.

Blanche’s numbers in Arkansas are weak. She’s vulnerable in the general, running behind all four of her Republican opponents. But before she can get to the general, she’s got to get through a primary, and 80% of Arkansas Democrats favor a public option.

Arkansas is also a really cheap state to run a Senate race in because of low population and cost of the media market, so it’s fertile primary ground. You want to take on someone in New York? Good luck with that. But in Arkansas, an incumbent’s ability to out-raise a primary challgner has much more limited value. There’s only so much TV air time you can buy.

Lincoln lives in the western part of the state, not in the Little Rock area, and she’s got Liddy Dole syndrome — she’s never in Arkansas. She spends most of her time in DC, which is one of the reasons her popularity is flagging. She’s not beloved like Mark Pryor, nor is she a lynchpin in the state party’s political machine.

At a recent town hall Lincoln was hammered with questions by Democrats about her position on the public option. They would forgive her for voting against one, but she’s taking a huge risk if she takes the unprecedented move of blocking it from coming to a vote in the Senate. Arkansas Dems who might otherwise think twice about taking on a sitting Senator would be much more inclined to step into a race amidst a climate of local Democratic disenchantment and a — shall we say “optimized” national fundraising environment.

Lincoln continues to poke the unions with a sharp stick, reiterating her intention to join a Republican filibuster of the Employee Free Choice Act. She’s done just about everything she can, and then a bit more, to align the heavens in favor of a primary challenger. If she takes that final step and joins a filibuster, she could potentially open the floodgates.

I frankly don’t think she’s that brave, but as one of the many who has long since tired of having the corporatist Dems like Lincoln write every piece of legislation that comes before the Senate, I sure would like to see her try.