His presser’s airing now. Another seat to defend next year in a state that’s already trending blue.

Good news for the Capitol staff, though: they probably won’t have to change the nameplate on his door.

Update: His likely successor as nominee is Rep. Tom Davis, whom the left has already started a file on. Note the Walter Reed and Schiavo items, in particular.

Update: On the other hand, re: Mark Warner, he did unexpectedly drop out of the presidential race last year when everyone thought for sure he’d be running, allegedly to spend more time with his kids but reportedly because he’s got a skeleton in his closet that would have sunk him if he’d run. Radar had a theory about it at the time. If it’s true, it might not keep him out of the Senate. Sexual indiscretion isn’t a real strong weapon for the GOP these days.

Update: It gets worse:

On the Republican side, Rep. Thomas M. Davis III (Va.) has long coveted Warner’s seat and has worked assiduously to position himself for a run. A moderate, Davis would probably have serious competition from conservatives, possibly from former governor James S. Gilmore III.

A Davis candidacy would have a domino effect in Fairfax County. Board of Supervisors Chairman Gerald E. Connolly (D), who has refused to commit to finishing his term if reelected in November, has made no secret of his interest in succeeding Davis in the 11th District, where Democrats are gaining strength. Former representative Leslie Byrne has been mentioned as another possible contender.

Update: In yet more good news, it seems Davis is even more of a “maverick” than John Warner is.

Update: Davis wastes no time.