WASHINGTON (AFP) - Republican Bob McDonnell has won the Virginia governor's race, sweeping his party to power in the pivotal swing state after nearly a decade of Democratic control.

With nearly all precincts reporting, the former state attorney general held 59 percent of the Tuesday vote, with his Democratic challenger, 18-year state senator Creigh Deeds, lagging far behind with just 41 percent in the state that helped propel President Barack Obama into office a year ago as the nation's first black president.

The outcome was part of a Republican one-two punch in key gubernatorial races in Virginia and New Jersey, where Republican Chris Christie defeated incumbent governor Jon Corzine in the heavily Democratic state.

Republicans hailed the victory in Virginia as a repudiation of Obama's performance since his inauguration in January.

"The Republican Party's overwhelming victory in Virginia is a blow to President Obama and the Democrat Party," Republican National Committee (RNC) Chairman Michael Steele said in a statement.

"It sends a clear signal that voters have had enough of the president's liberal agenda."

But Edison Research exit polls showed that 55 percent of Virginia voters said Obama did not factor into their decision.

"You have allowed me to represent our vision and aspirations in one of the most pivotal elections in Virginia history," McDonnell, 55, said in his acceptance speech. "And I will not let you down."

Deeds, 51, vowed he would fight on.

"Just because we didn't get the right result tonight doesn't mean we get to go home and whine," he told supporters. "We still have fight, we still have spirit."

McDonnell, a conservative Republican, follows two Democrats in taking over as the governor's mansion.

Amid worries over the economy and the tough battle in Congress over Obama's plans to overhaul the US health care system, Deeds faced an uphill battle in securing critical moderate and independent votes. A stunning 89 percent of voters in New Jersey and 85 percent of Virginians surveyed in exit polls said they were worried about the state of the economy.

Obama had some skin in the game, having campaigned for Deeds in Virginia, but McDonnell's sweep -- along with Republican wins for the lieutenant governor and attorney general seats -- signaled Democrats may not be able to count on Obama's star power alone to carry them through key mid-term elections next year.

Former Virginia governor Tim Kaine, the chairman of the Democratic party, said Obama remains popular even in Virginia where his approval rating stands at 57 percent.

But the vote was a blow for Democrats who had hoped Obama's presidential win in Virginia -- the first time the state had backed a Democratic presidential contender in over four decades -- was a sign that the formerly conservative state had taken a permanent swing away from the Republicans.

Instead, the state continued its trend of backing the party not in the White House.

"Bob McDonnell's victory gives Republicans tremendous momentum heading into 2010," said Republican Governors Association Chairman Haley Barbour.

"Virginia is an important swing state that had been trending blue (Democratic) for 12 years."

The association's vice chairman, Minnesota Governor Tim Pawlenty, said "winning Virginia was essential to the rebuilding of our party."

Steele told CNN that "people are going to respond next year if they don't think the direction that the administration and the Congress are going in is the one they think the country should go in."

But Democrats won a consolation prize of sorts with a surprise victory in a special congressional election by Democratic candidate Bill Owens in a traditionally Republican upstate New York district.

His win came after a bitter feud among Republicans that saw the party's official candidate, Dede Scozzafava, drop out of the race and endorse Owens over Conservative Party candidate Doug Hoffman.