Obenshain plans to concede on Wednesday, as a recount of the race nears its end. Obenshain had been trailing state Sen. Mark Herring (D) in initial estimates of the recount.
Herring narrowly beat Obenshain in the November election. Herring's margin of victory was small enough that under Virginia law Obenshain could request a recount.
A Herring victory means that Democrats will have swept the top three political positions in the state. Terry McAuliffe (D) was elected governor and state Sen. Ralph Northam (D) was elected lieutenant governor.