WASHINGTON — Republicans wrested political control of Virginia from the Democrats on Tuesday and New Jersey's unpopular Democratic Gov. Jon Corzine was fighting for his political life as independent voters swung behind the GOP in both states. It was a troubling sign for President Barack Obama and his party heading into an important midterm election year.

Republican Gov.-elect Bob McDonnell's victory in Virginia over Democrat R. Creigh Deeds was a triumph for a GOP looking to rebuild after being booted from power in national elections in 2006 and 2008. It also was a setback for the White House in a swing state that was a crucial part of Obama's electoral landslide just a year ago.

In New Jersey, exit polls showed Corzine locked in a close race, with independents heavily favoring his Republican challenger Chris Christie in a three-way contest with independent Chris Daggett.

The president had personally campaigned for Deeds and Corzine, raising the stakes in low-energy off-year elections.

Early returns in Virginia showed that by a 2-1 margin McDonnell was winning rapidly growing, far-flung Washington, D.C., suburbs — places like Loudoun and Prince William counties — that Republicans historically have won but that Obama prevailed in last fall by winning over swing voters.

Democrats had won big victories in Virginia in 2006 and 2008 and consider New Jersey a stronghold.

But interviews with voters leaving polling stations in both states on Tuesday were filled with reasons for Democrats to be concerned and for Republicans to be optimistic.

Independents — the crown jewel of elections because they often determine outcomes — were a critical part of the diverse coalition that carried the president to victory in Virginia and across the country. But after more than a year of recession, still early in Obama's term, they fled from Democrats in a state where the economy trumped all. And exit polls indicated they were doing the same in New Jersey.

The Associated Press exit polls showed that nearly a third of voters in Virginia described themselves as independents on Tuesday, and nearly as many in New Jersey did. They preferred McDonnell by almost a 2-1 margin over Deeds in Virginia, and Christie over Corzine by a similar margin — one year after breaking heavily toward Obama in both states.

The surveys also suggested the Democrats had difficulty turning out their base, including the swarms of first-time minority and youth voters whom Obama attracted as part of his coalition. The Virginia electorate was whiter in 2009 than it was in 2008, when blacks and Hispanics turned out in droves to elect the country's first black president.

In both states this year, voters said their top concern was the economy.

More than four in 10 voters in Virginia said their view of Obama factored into their choice on Tuesday, and those voters roughly split between expressing support and opposition for the president. People who said they disapprove of Obama's job performance voted overwhelmingly Republican, and those who approve of the president favored Deeds, the Democrat.

The Obama factor was similar in New Jersey, though there were slightly more voters who said the president did not factor into their choice.