Virginia Democrats’ hopes of maintaining their party’s hold on the Commonwealth’s upper house were very much in doubt late Tuesday, hinging on a razor-thin count in a single Senate district.

When the ballot-counting ended for the night, longtime Spotsylvania incumbent Sen. R. Edward Houck (D) was 86 votes behind Republican challenger Bryce E. Reeves. Absentee ballots have been counted, and an unknown number of provisional ballots will be counted Wednesday.

Gov. Robert F. McDonnell (R) early Wednesday morning declared victory on behalf of Reeves in the 17th district, which encompasses Fredericksburg and parts of five downstate counties.

Craig Bieber, Houck’s campaign manager, said the race “remains too close to call” and noted “several significant discrepancies during Tuesday night’s tabulation that deserve further attention during the canvassing and certification process.”

Republicans need a net gain of three seats to seize outright control of the Senate; a two-seat gain would leave the GOP with a working majority on the Senate floor, with Lt. Gov. Bill Bolling able to break tie votes, but unable to dominate committees.

A clear GOP pickup appeared in a newly drawn Southside Senate district pitting two incumbents, where Sen. Bill Stanley (R) held a 643-vote lead on Sen. W. Roscoe Reynolds (D) with all precincts reporting. The second pickup hinges on the outcome of the Houck-Reeves race.

Houck’s narrow deficit came as other incumbent Democratic senators appeared to seize victory in closely contested races.

In high-profile suburban contests, Sen. Charles J. Colgan Sr. (D-Manassas) was comfortably ahead of challenger Tom T. Gordy (R) with all but one precinct counted. Sen. Linda “Toddy” Puller (D-Fairfax) held a significant lead over former delegate and state GOP chairman Jeffrey M. Frederick with 90 percent of the vote in. Republicans had high hopes of ousting Sen. George L. Barker (D-Fairfax), but attorney M. Miller Baker was running behind with more than three-quarters of the vote counted.

Former Del. Dick Black (R) also handily outpolled J. Shawn Mitchell (D) in a formerly Republican Senate district spanning Loudoun and Prince William counties.

In a closely watched House race downstate, Del. Ward L. Armstrong (D-Henry), the House minority leader, ran more than five points behind Republican Del. Charles D. Poindexter with all precincts reporting. Armstrong’s district was redrawn by House Republicans this year in a move widely interpreted as an attempt to oust Armstrong.

McDonnell said Tuesday night the GOP had added at least six seats, perhaps as many as nine, to its already dominant 20-seat House majority.

In Northern Virginia local races, one Fairfax County Board of Supervisors race expected to be closely decided lived up to billing. With about 90 percent of precincts in, Republican incumbent John C. Cook outpolled Democrat Janet S. Oleszek by less than a percentage point in their battle for the Braddock District seat. No other board race was nearly so tight, with Chairman Sharon S. Bulova cruising to a second term over three opponents in early returns.

In Fairfax school board races, longtime Dranesville incumbent Jane K. Strauss was outpolling newcomer Louise K. Epstein by about 600 votes with 90 percent of precincts reporting just after midnight. But other school board incumbents were winning more comfortably — Ilryong Moon (at-large), Daniel G. Storck (Mount Vernon) and Kathy L. Smith (Sully).

Prince William County races, though hotly contested, did not appear to be particularly close. With two-thirds of precincts reporting, Corey A. Stewart (R), incumbent chairman of the Board of County Supervisors, appeared headed to an easy victory over Babur Lateef (D) and John S. Gray (I).

In a contentious Gainesville district race, Republican Peter K. Candland had opened a significant lead on Democrat Ann B. Wheeler, with 11 of 12 precincts reporting. Incumbents in contested races — Martin E. Nohe (R-Coles) and Frank J. Principi (D-Woodbridge) — both led comfortably with more than 90 percent of the vote in.

The results started trickling in after a day of low voter turnout, accompanied by sporadic reports of voter confusion as people showed up to cast ballots and discovered their polling place had changed because of redistricting.

The state Board of Elections said there had been “isolated issues” at some polls but characterized them as “normal Election Day issues.”

In the Washington region, some counties reported only a handful of problems on Election Day, but others experienced dozens of baffled voters at individual polling places. That was most often the case in Fairfax County, due to redistricting.

But local elections officials characterized the problems on Tuesday as minor.

Carol Ann Coryell, secretary of the Fairfax County’s Electoral Board, said that after visiting some precincts and talking with Office of Elections staff in the field, she has heard of only routine glitches involving voting machines and only minor post-redistricting confusion among voters.

Overall, turnout was spotty, with some precincts reporting unusually heavy voting while others struggled to reach even the 30 percent that was expected statewide.

Though state legislative elections will determine control of the Virginia Senate, some voters said they were drawn to vote as much by national politics as by the local and General Assembly races.

“I’m a liberal Democrat and the conservative trend scares me,” said Gary Buffington, 61, a retired Census Bureau statistician, who was voting with his wife, Mary, at Francis Scott Key Middle School in Franconia.

He and his wife voted for Sen. George Barker (D), hoping not only to keep him in office but also to thwart GOP hopes for a Senate takeover.

Strong supporters of President Obama, they also wanted to send a pro-Democrat message.

“The obstructionist attitude of the Republican Party is what bothers me most,” Gary Buffington said. “Nothing’s getting passed” in Washington.

Some voters said they eagerly await the 2012 election, when the next president will be determined.

“Unfortunately, I have to wait for next year to vote in the one I care most about,” said Tom Mills, retired after 23 years of service in the Army, walking into Hayfield Elementary School in Fairfax County and talking about Obama. “I think he’s a rampant socialist, if not a communist. Everything he does is against America.”

Northern Virginia than they invest back in

Of all the local issues, traffic is a perennial thorn, he said. He spent years doing a 40-mile commute that could take an hour and a half or two hours each way, he said, and never got used to it. “I hated it the first day and hated it the day I quit.”

In Maryland, voters went to the polls for elections in Bowie, College Park, Gaithersburg, Greenbelt, Rockville and Takoma Park.

Staff writers Jeremy Borden, Caitlin Gibson, Anita Kumar, Fredrick Kunkle, Patricia Sullivan and Laura Vozzella contributed to this report.

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