Republicans swept to victory in two critical governor's races Tuesday, with independent voters helping deliver twin setbacks to Democrats who hoped to consolidate gains scored by President Obama last year.
GOP victories in Virginia and New Jersey were fueled by unease over the economy and growing skepticism of government, according to exit polls.
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Obama carried both states last year. But the GOP gubernatorial candidate racked up huge margins among independent voters, notwithstanding the White House's efforts to boost the Democrats.
Republican Bob McDonnell won the race in Virginia, beating Democrat Creigh Deeds. It marks the first time Republicans won a governor's race in the state since 1997.
And in New Jersey, Gov. Jon Corzine, D-N.J., was defeated in his reelection bid by former federal prosecutor Chris Christie. The heavily Democratic state was considered the party's best chance to steal a victory in a tough electoral climate.
The results are likely to be interpreted as a rebuke of the president and Democrats in Congress, though Democrats cautioned that the results should not be over-interpreted.
The losses -- and particularly the cratering of support among independents -- could complicate the president's push to get wavering lawmakers to support health care reform this year.
Democrats found their lone bright spot in upstate New York, in a wild race for a vacant House seat. Bill Owens defeated Conservative Party candidate Doug Hoffman, in a race that highlighted fractures inside the GOP that resulted in the Republican candidate dropping out of the race and endorsing Owens.
Republicans hailed the early returns as a sign of a GOP comeback.
"I fully expect this trend to continue in the coming months," said Michael Steele, the chairman of the Republican National Committee, "and President Obama and Democrats should have reason to fear the upcoming elections in 2010."
A White House spokesman told ABC's Jake Tapper that the president is not watching election results on television tonight.
Faced with the prospect of a grim Election Day 2009, Democrats were hoping that Corzine would provide a glimmer of positive news out of New Jersey.
Leading Democrats sought to emphasize the local characteristics they said would drive voters' decision-making in an off-year election.
"People need to be very cautious about drawing conclusions about the outcome of these elections," Rep. Chris Van Hollen, D-Md., the chairman of the Democratic Congressional Campaign Committee, said on ABCNews.com's "Top Line" Tuesday.
"I don't think the president is looking at these and believes that they say anything about our future legislative efforts or our future political efforts," White House Press Secretary Robert Gibbs said of the two gubernatorial races.
Preliminary exit polls suggest that voters largely support the president: 57 percent of voters in New Jersey and 51 percent in Virginia said they approve of Obama's job performance. A distinct minority of voters said their votes were connected to the president's leadership.
But 46 percent of New Jersey voters and 53 percent in Virginia said government is "doing too many things," suggesting unease with the scope of the president's agenda.
The president and his agenda were clearly on many voters' minds Tuesday. Wayne Rippy, a supporter of Republican gubernatorial candidate Bob McDonnell, wore an anti-stimulus "Tea Party" button to his polling place in Arlington, Va. -- a reminder of the anti-government fervor that's still simmering across the nation.
"We're looking for a change, but not the change Obama has brought us," Rippy said.
In other major races, New York City voters awarded a third term to Mayor Michael Bloomberg, now an independent, despite voter anger over his successful effort to overturn term limits that would have forced him out of office, according to an Associated Press projection. Other cities including Atlanta, Boston, Houston, Detroit, and Pittsburgh also chose mayors.
California's lieutenant governor, John Garamendi, is expected to a Northern California House seat in Democratic hands. And voters in Maine and Washington State are registering votes on same-sex marriage.
CLICK: Virginia Governor's Race
New Jersey Governor's Race
Gov. Corzine faced the kind of tight reelection race that -- unless the economy turns around fast -- incumbents of both parties may grow to expect in 2010.
Christie, the Republican candidate tapped into distaste for New Jersey Democratic machine politics and Corzine himself, in a race complicated by the presence of self-funded independent candidate Chris Daggett.
Christie surged in polls in the race's closing days, despite the heavy Democratic advantage in the Garden State.
And he swamped Corzine among independent voters, with 58 percent to Corzine's 31 percent, according to exit polls.
That more than canceled out any advantage Obama himself could confer on Corzine, his former Senate colleague who was elected governor in 2005.
The White House has put more on the line politically in New Jersey than in any other of the 2009 races, sensing an opportunity to register a blue dot in a red year.
"Here's the tough part," the president said at a Corzine rally Sunday. "Here's the time when it's not as sexy, it's not as flashy. You know, this is when governing comes in, and we've got to make tough choices. And progress isn't always as quick as we want it."
CLICK: New Jersey Governor's Race
Virginia Governor's Race
The president's victory in Virginia last year -- the first Democratic presidential win in the Old Dominion State in 44 years -- was hailed a potential turning point in the heart of the Deep South.
But after winning two straight gubernatorial races in Virginia, Democrats gave back ground with McDonnell's victory, in what appears to be a state-wide GOP sweep of major offices.
McDonnell outpaced Deeds among independents in Virginia, according to exit polls, despite Obama's strong showing among unaligned voters last year.
And Virginia voters expressed severe concerns about the economy: 85 percent of voters said they were worried about the direction of the economy over the next year.
McDonnell tapped into those concerns with a sharp emphasis on the economy and job creation, despite Democrats' efforts to make the campaign turn on social issues.
"There are a couple of things that transcends politics, and that's first and foremost, we're all Virginians, and we're all Americans," McDonnell said at his celebration event in Richmond. "We had independents and Democrats that came over to support us."
The president himself campaigned for Deeds in Virginia last week. Some of his aides, however, privately signaled last month that they thought Deeds -- hardly an impressive campaigner -- was likely to lose.
Deeds conceded defeat shortly after 9 pm ET: "We've got a whole pile of work ahead of us, and just because we didn't get the right result tonight, doesn't mean we get to go home and whine," said Deeds. "We've got to keep working, and keep fighting. And I'm fighting!"
Democrats point out that the party in the White House has lost the governor's mansion in Richmond in every election since 1973.
But the race is a setback to Democrats' hopes to realign the electoral map in a big Southern state. And it questions whether it's possible for Democrats to motivate independents and those who haven't voted frequently in the past without a candidate named "Obama" on the ballot.
ABC News' Steven Portnoy, Aaron Katersky, and David Chalian contributed to this report.