Arlington County voters today will help decide several contested state and local races -- and perhaps control of the Virginia General Assembly for at least the next two years.

At the forefront is Arlington County Board Member Barbara Favola, who survived a bitter and expensive state Senate primary battle in order to face the well-funded Republican Caren Merrick, a McLean businesswoman. The winner will succeed retiring Sen. Mary Margaret Whipple.

Republican Gov. Bob McDonnell has been campaigning off and on in Northern Virginia for months, trying to amplify any patches of red in this typically blue portion of the state.

He helped Merrick raise money early on and took the guest spot at a recent Arlington fundraiser for Republican Patrick Forrest. Forrest is facing longtime Democratic Sen. Janet Howell for the 32nd Senate District seat that represents parts of Arlington and Fairfax counties.

All of this is against the backdrop of the Democrats' tenuous 22-18 hold on the General Assembly's upper chamber. Republicans control the House.

Favola has called her opponent an agent of a radical right-wing agenda and paints her as someone who will loosen gun restrictions and be an enemy of abortion rights and gay rights.

Merrick has said those issues haven't come up on the campaign trail, that she's focused on what voters care about -- jobs and the economy.

The seat they're fighting over in the 31st District includes the Rosslyn-Ballston corridor, and stretches into Fairfax and Loudoun counties. And Favola has cautioned her supporters that the precincts in Fairfax County in particular have a history of turning out more voters on off-year elections than Arlington.

McDonnell's campaign already has announced a post-election press conference to talk election results. Arlington Democrats are holding a victory celebration Tuesday night at Bailey's Sports Grille in Ballston Common Mall.

Arlington voters also will determine who sits on the County Board for the next four years. Two seats are open. Incumbent Democratic Board members Mary Hynes and Walter Tejada are facing Green Party challenger Audrey Clement, who has forced the issue of local officials' relationship with developers.

Clement said in a recent interview that she hopes to pick up votes in areas where people may be upset with controversial board decisions -- particularly in the Columbia Pike and Crystal City areas.

Arlington also includes:

• State Senate District 30, a race between Democrat Adam Ebbin, a sitting House member, and Republican Timothy McGhee. Ebbin is openly gay, and McGhee has made controversial comments to gay voters.
• The 48th House District, which includes an area that runs along the Potomac River from just north of Potomac Yards through Rosslyn and on to the Maryland line before cutting over to West McLean in Fairfax County. Incumbent Del. Bob Brink faces Independent Green Party candidate Janet Murphy and independent candidate Kathy Gillette-Mallard.
• Unopposed races for Democratic Del. David Englin in the 45th House District, Democratic Del. Patrick Hope in the 47th House District, Democrat Alfonso Lopez in the 49th House District, Democrat Theo Stamos for the job of commonwealth's attorney for Arlington and Falls Church, Arlington Sheriff Beth Arthur, Arlington County Revenue Commissioner Ingrid Morroy, Arlington County Treasurer Frank O'Leary and Arlington Public Schools Board member Abigail Raphael.

Polls are open from 6 a.m. to 7 p.m. today.

Click here for a list of polling places.