It's been overshadowed by the presidential race, but Virginia voters are casting ballots Tuesday in a key U.S. Senate race.

Two former Virginia governors, Democrat Mark Warner and Republican Jim Gilmore, are seeking the seat held by retiring Republican John Warner.

A victory by Mark Warner would give Democrats control of both Virginia Senate seats for the first time since 1970, when Harry F. Byrd Jr. left the party and declared himself an independent.

Democrats are hoping to gain a 60-seat majority in the Senate, which would allow them to defeat any Republican filibusters. Many political analysts see Virginia as Democrats' best chance nationally to pick up a seat.

John Warner, retiring after 30 years in the Senate, endorsed neither candidate.

Democrats are also expected to gain at least one seat in Virginia's elections for the U.S. House of Representatives.

Republicans currently hold an eight-to-three advantage in the Virginia delegation. But Democrat Gerald Connolly, chairman of the Fairfax County Board of Supervisors, is favored to win the northern Virginia seat being vacated by retiring Republican Tom Davis. Republicans Thelma Drake and Virgil Goode also face strong Democratic challenges Tuesday.

If any incumbents lose, it will be unusual. The last U.S. House member from Virginia to lose re-election was Democrat Leslie Byrne in 1994.

Nine of the state's 11 seats are contested. Only Democrats Bobby Scott and Rick Boucher are getting a free pass.