Rep. Parker Griffith (D-Ala.) is expected to become the second member of Congress this year to switch parties, according to a report by Politico. Griffith, a freshman in a historically-Democratic yet vulnerable district, will announce his decision this afternoon in Alabama and denounce the health care reform bill as a main reason for the move.

From Politico:

Griffith's party switch comes on the eve of a pivotal congressional health care vote and will send a jolt through a Democratic House Caucus that has already been unnerved by the recent retirements of a handful of members who, like Griffith, hail from districts that offer prime pickup opportunities for the GOP in 2010.

The switch represents a coup for House Republican leadership, which had been courting Griffith since he publicly criticized Democratic leadership in the wake of raucous town halls over the summer.

Although Alabama's 5th District has voted Republican in every presidential contest since 1980, it has never elected a Republican to Congress. It covers the entire northern border of the state and includes Huntsville. Griffith succeeded nine-term Rep. Bud Cramer (D) after just a 3-point victory last year, when John McCain won the district with 61% of the vote.

Pennsylvania Sen. Arlen Specter switched from the Republican to Democratic Party earlier this year to avoid a tough GOP primary. However, Specter now faces an incredibly challenging Democratic primary, and -- should he win -- a difficult general election battle.

Griffith could face GOP primary opposition, as two Republicans had already announced they were running to challenge him -- Madison County Commissioner Mo Brooks and businessman Les Phillip, a Navy veteran.

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