Over at Election Reference, they have an e-mail from Snohomish County councilman John Koster that he will take on six-term Democrat Rep. Rick Larsen in Washington’s 2nd congressional district. Koster took on Larsen in the 2010 midterms and came oh-so-close to victory, 48.9 percent to 50 percent, a difference of about 6,000 votes out of 303,000 cast.

This district is the state’s northwestern corner; it currently scores a D+3 in the Cook Partisan Voting Index. The district is almost certain to look different in 2012 (Washington is gaining a seat in redistricting) but the Election Reference guys conclude, “Depending on the composition of the second congressional district after redistricting, Rep. Rick Larsen may decide to retire or more to another district… This seat is one of the GOP’s best chances at a pickup over an incumbent. If the NRCC decides to go on offense this cycle, this seat should be at the top of the list.”