Republicans seized control of the House on Tuesday and shrank the Democratic advantage in the Senate, dealing a major setback to President Obama and sweeping a number of "tea party" insurgents into power.
The nearly coast-to-coast blowout -- a result of voters' frustration and deep economic anxiety -- promised to once more change the country's political dynamic, presenting challenges to both parties in a newly divided government.
Obama, who pushed through the most expansive legislative agenda of any president in generations, could spend the remainder of his term just trying to preserve what he has accomplished. Republicans, with a measure of power, will share some responsibility for governing and may have to do more than simply thwart the president and his fellow Democrats -- or face a similar repudiation by voters in 2012.
"This is not a time for celebration," he said. "Not when 1 in 10 of our fellow citizens are out of work. Not when we buried our children under a mountain of debt. Not when our Congress is held in such low esteem."
Obama, who called Boehner around midnight to give his congratulations, planned to offer his reaction at a news conference Wednesday.
The election results, a likely gain of 60 or more seats for Republicans, were like a steam release after months of building pressure and amounted to the biggest turnover since the GOP won 52 House seats in 1994 -- the last time Democrats controlled both Congress and the presidency.
Republicans won House seats in virtually every part of the country, gaining bunches in the hard-pressed industrial Midwest and toppling incumbents in Virginia, Texas, New Hampshire and Florida.
The Democrats fared better in races for the Senate, hanging onto the majority by a handful of seats. Their leader, Harry Reid of Nevada, was reelected by a surprisingly comfortable margin over tea party favorite Sharron Angle.
The Senate contests produced mixed results for the nascent tea party movement. Rand Paul, a founder of the Kentucky branch, notched a victory, Marco Rubio won in Florida and Mike Lee won in Utah.
But Christine O'Donnell lost in Delaware, a seat both parties had put in the GOP category until the centrist Rep. Michael N. Castle lost the Republican primary. In Nevada, Angle was seen as the weakest of Reid's potential opponents.
Voters also chose governors in 37 states, electing Democrats Jerry Brown in California and Andrew Cuomo in New York. Republican Nikki Haley posted a tea party victory in South Carolina and the GOP ousted Democrat Ted Strickland in Ohio.
In some ways, Democrats were fighting political forces beyond their control. Midterm elections are inevitably a referendum on the party holding the White House and almost always result in congressional losses.
This year, Democrats were defending a sizable number of incumbents, having picked up more than 50 House seats in the last two elections, including many in GOP-leaning districts. That put the party on the defensive from the start.
On top of that, the economy was the worst it had been in over a generation, with unemployment approaching 10% and bankruptcy and home foreclosure rates soaring. The result was a combustible mix of nervousness and anger; about 4 in 10 voters said they were worse off financially than two years ago, according to exit polls.
The party's problems were exacerbated by the ambitious -- critics called it overreaching -- agenda pursued by Obama and the Democrats controlling Congress. They muscled through a massive healthcare overhaul, bailed out the auto industry and passed an $800-billion economic stimulus bill, all in about a year's time.
The president and his allies said the measures were needed to rescue the economy from its worst downturn since the Great Depression, and Obama argued right through election day that the measures were working.
"Things have gotten better over the last two years," Obama said in a round of interviews Tuesday with radio stations in several key states. "We can only keep it up if I've got some friends and allies in Congress and statehouses."
But critics said the Democrats had exploited the financial crisis to wrench the country too far left, expanding the size and scope of the government in ways most Americans never imagined when they embraced Obama's promise of change back in 2008. They urged voters to push back at polls.
Republicans were vague, promising tax and spending cuts without offering much detail or explaining how they would reduce the federal deficit.
But that seemed not to matter. Unsettled voters were looking to vent their displeasure and Democrats were the obvious target; more than 1 in 3 voters polled said they cast their ballots to express unhappiness with Obama.
"The way American politics works is if you're in control of everything, you get blamed for everything," said William Galston, a senior fellow at Washington's Brookings Institution.
The midterm election featured record spending -- nearly $4 billion -- and an unrelenting blitz of negative advertising. For many voters, the overriding sentiment Tuesday was neither joy nor disappointment, but relief that the long, vituperative campaign season was finally over.
"I'm so sick of the commercials, from both sides," said Kandyce Douglas of Las Vegas, a retail manager who cast her ballot for Reid. "It turned my stomach."
Losing the House could greatly complicate Obama's next two years in office. Republicans have vowed to roll back the president's signature healthcare bill and wield their subpoena power on Capitol Hill to launch a series of investigations.
Efforts to address immigration and climate change -- the two biggest issues remaining on the president's legislative agenda -- could be exceedingly difficult, given the vast gulf between Democrats and an energized, more conservative Republican contingent.
Even before the polls closed, the postmortems -- and Democratic self-criticism -- began.
Appearing on CBS' "Early Show," Pennsylvania Gov. Edward G. Rendell, a former Democratic National Committee chairman, said Democrats had to "learn to explain and communicate what we've done and what we want to do a lot more clearly."
Republicans suggested it was the Democrats' policies, not their communication skills, that needed changing.
Mississippi Gov. Haley Barbour, chairman of the Republican Governors Assn. and head of the national GOP during the 1994 landslide, said on NBC's "Today Show" that Republicans were "going to be cutting spending. They're going to try to repeal and replace the healthcare reform bill. If they can't repeal it, they're going to try to change it so that you wouldn't recognize it."
However, Republicans run the risk of overstepping just as they said Democrats had done. Exit polls showed voters no more enamored of the GOP than the party in power; more than half of those surveyed held negative views of both major parties.
"Republicans are about to learn that the game changes once you have a real share of power," said Galston, who served in the Clinton White House before and after the 1994 Democratic shellacking. "Then you're no longer a part of the opposition; you've got to be a part of the solution. And if you're not, you'll be punished."
Times staff writers P.J. Huffstutter in Las Vegas and Richard Simon in Washington contributed to this report.
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'I know things are still tough out there, but we finally have job growth again. ? It is all at risk if people don't turn out and vote today.'
-- President Obama
'For those who think the government is spending too much and bailing out too many, this is their opportunity to be heard.'
-- John A. Boehner, House Republican leader
'I will honestly say that I voted for [Obama] two years ago. And I want my vote back.'
-- Sally McCabe, 56, of Plymouth, Minn.
'I still have faith in Obama and his vision, though I think he's strayed a little too far to the left. But the "tea party" types scare me.'
-- Jordan Howlett, 44, of Toms River, N.J.
'I just want this day to be over. Because it's been too much political ads, newscasts, too much talking heads. I just want to move on and get this country back.'
-- Steve Wise, 28, of Miami
'Republicans are going to try to repeal and replace the healthcare reform bill. If they can't repeal it, they're going to try to change it so that you wouldn't recognize it.'
-- Haley Barbour, governor of Mississippi
'It's a cycle. The economy is going to improve. I don't blame the current administration and I don't blame the Bush administration.'
-- Gary Stulir of Smyrna, Del.
'I have a message, a message from the people of Kentucky, a message that is loud and clear and does not mince words: We've come to take our government back.'
-- Rand Paul, a "tea party" Republican who won a U.S. Senate seat
'Politics might not thrill me. But democracy rocks.'
-- Susy Kosh, 37, of Dripping Springs, Texas