{mosads}Four Democrats in centrist- or Republican-leaning districts have already said they won’t run again in 2010: Reps. Brian Baird (Wash.), Bart Gordon (Tenn.), John Tanner (Tenn.) and Dennis Moore (Kan.). Rep. Parker Griffith (Ala.) also left the Democratic Party to become a Republican earlier this month.

Analysts have projected that Republicans are likely to make inroads against Democrats’ 79-seat majority in the House, which Boren cited as a reason for additional retirements.

“The political environment is definitely a contributing factor,” he said. “Some may decide they want to do something else for a few years.”

Boren is one of the most conservative House Democrats, having supported the stimulus bill but opposing cap-and-trade legislation and the House healthcare bill.

He told The Oklahoman, though, that he won’t switch parties like Griffith did. The nonpartisan Cook Political Report rates Boren’s district, despite its strong Republican leanings, as having a strong likelihood for Democratic retention in 2010.

This post was updated at 11:30 a.m.