RICHMOND, Va. (AP) -- Del. Bill Carrico will seek the seat left empty by the retirement last week of fellow Republican state Sen. William Wampler of Bristol.

Monday's announcement helps shape November elections that determine whether Republican Gov. Bob McDonnell can institute his conservative vision of state government during his final two years in office.

With a net gain of two Senate seats, Republicans could take back the state Senate majority the Democrats won in 2007. That would put both General Assembly chambers and the governor's office under GOP dominance for the first time in 10 years.

Carrico, a former state trooper from Grayson popular with the GOP right, announced his plans as a Republican moderate, Chesapeake's Sen. Harry Blevins, said he will seek re-election even as he battles prostate cancer.