Republican hopes for an effective majority in the Senate and a historic power grab in Richmond were pinned late Tuesday on a central Virginia race in which a GOP challenger clung to an 86-vote lead with a final count not expected until Wednesday.
The battle for the 40-member state Senate was far tighter than the GOP had hoped and many political observers had expected, with Republicans who had identified as many as 10 winnable seats decisively winning just one.
The deciding race left former detective and Army Ranger Bryce E. Reeves, a Republican, with just a double-digit lead over longtime incumbent Sen. R. Edward Houck, a Democrat, out of more than 45,000 ballots cast in the conservative-leaning district around Fredericksburg, Va.
Complicating matters, the unofficial vote tally assembled by the Virginia Board of Elections was at odds with a vote tally released Tuesday night by the Associated Press, which had Mr. Houck ahead by 204 votes. The news organization later adjusted its total to reflect the preliminary numbers from the elections boards and deemed the race “too close to call.”
An unknown number of provisional ballots had yet to be counted, a task elections officials say takes place after Election Day. Because the candidates were separated by less than 1 percent of the vote, Mr. Houck under state law also would be entitled to request a recount.
Mr. McDonnell also issued a statement early Wednesday saying that Republicans had picked up two seats in the Senate and expanded their majority in the House of Delegates by at least six seats, “the highest number Republicans have ever had in that body.”
“Tonight, Virginia voters have made history,” he said.
Republican control of the Senate would complete a GOP sweep of state government that began in 2009, giving the party a 20-20 tie in the General Assembly’s upper chamber, with GOP Lt. Gov. Bill Bolling casting tie-breaking votes as needed.
Republicans had been hopeful that Virginia voters, notorious for eschewing the party in power in Washington, would deliver for them, after GOP candidates won the top three statewide elected offices in 2009 and picked up three congressional seats in the 2010 midterms.
Party leaders speculated that a sluggish national economy and increasingly poor job-approval ratings for President Obama would help them win control of the governor’s mansion and both chambers of the General Assembly for the first time in a decade and only the second time since the Civil War.
Democrats began the day with a 22-18 advantage in the Senate. Holding on to the Senate would provide a Democratic Party badly in need of momentum with some good news heading into next year’s elections, when Mr. Obama looks to repeat his 2008 win in a state critical to his re-election chances.
After the votes were counted, several seats that Republicans had identified as competitive were still held by Democrats.
In Northern Virginia, incumbent senators in close races held their ground. Sen. Charles J. Colgan, Prince William Democrat, fended off a late charge from Republican Tom Gordy, the president of a military nonprofit.
Longtime Sen. Linda “Toddy” Puller, Fairfax Democrat, narrowly defeated former Delegate and ousted Republican Party of Virginia Chairman Jeffrey M. Frederick, who was attempting a political comeback.