Rep. Tom Davis, R-Va. gestures during a news conference on Capitol Hill in Washington in this May 9, 2006 file photo. Davis announced Wednesday, Jan. 30, 2008, that he will not seek re-election to Congress, giving Democrats a strong opportunity to pick up a congressional seat in November. (AP Photo/Lauren Victoria Burke, File)

Rep. Tom Davis, R-Va., left, campaigns in Vienna, Va. on in this Nov. 6, 2006 file photo at the Vienna Metro stop. Davis announced on Wednesday Jan. 30, 2008 that he will not run for re-election in 2008. (AP Photo/Ron Edmonds, file)