As soon as Bill Halter announced he'd challenge Sen. Blanche Lincoln in the 2010 Democratic Senate primary, the progressive/netroots moneyraising machine kicked into gear with the support it had pledged to give him if he did, indeed, jump in: as of last night, $1 million had been raised for Halter by a coalition of MoveOn.org ($900k), the Progressive Campaign Change Committee & Democracy for America ($64k), and Daily Kos ($41k)--less than two days after Halter announced he would run.

Lincoln has been an object of liberal pressure for some time, as she represents a swing vote on progressive initiatives like the public option and the Employee Free Choice Act, and the liberal community made no bones about its glee when Halter entered the race (and said he supports the public option).

The question here isn't just whether Halter, the state's lieutenant governor, can beat Lincoln, but whether his campaign can appear formidable enough to force Lincoln into voting more liberally with Halter's primary threat looming on her left.

That said, while $1 million is a lot of money to raise so suddenly (Halter only announced his candidacy Monday morning--though liberals had presumably were ready for the fundraising effort before he made it public), it doesn't signify a major threat to Lincoln on its own: she had more than $5 million in her campaign war chest, as of her last Federal Election Commission filing. It does, however, mean Lincoln will have to spend significantly in her primary to defeat him. Rep. John Boozman (R-AR) looms as a marginal favorite on the GOP side, in terms of how he stacks up in polls against Democrats, but the GOP as other viable candidates in businessman Curtis Coleman, state Sen. Gilbert Baker, former state Sen. Jim Holt, and state Senate GOP Leader Kim Hendren.