Voters toppled House Speaker Nancy Pelosi from power Tuesday, four years after she became the first female speaker in history, handing the majority of the House of Representatives to Republicans in a landslide surpassing the historic election of 1994.

With polls closed but returns in the West still not tallied, Republicans had won 233 seats to the Democrats' 174. Republicans defeated 58 incumbent Democrats, a stunning blow to President Obama and well more than the 39 seats they needed to seize control of the House, walloping Democrats from Florida to Michigan as voter frustration with the anemic economy, near double-digit unemployment and the ballooning federal debt boiled over at the polling booth.

Democrats lost not only their marginal seats in the South, but also took a beating in the Ohio industrial heartland, swing-state Virginia and the West, regions that are pivotal in presidential elections.

Early returns showed Republican David Harmer leading Democratic incumbent Rep. Jerry McNerney in the East Bay.

While the Democratic majority in the Senate was diminished, Democrats held the upper chamber, easily winning a sharply contested seat in West Virginia to secure their Senate firewall. Republicans won at least six seats, short of the 10 seats they needed for a majority. Republicans ousted veteran Wisconsin Democratic liberal Russ Feingold, picked up Pennsylvania and captured the trophy Illinois Senate seat vacated by President Obama.

The amorphous but potent Tea Party, whose origins some political experts trace to a February 2009 rant by CNBC's Rick Santelli, was dismissed by veteran heavyweights in both parties but soon transformed the political landscape. The first sign of its potency at the ballot box was Republican Scott Brown's shocking upset to win the late Ted Kennedy's Senate seat in February.

Even as a wave of Democratic retirements opened the door to the GOP, Tea Party-backed candidates from Utah to Kentucky to South Carolina to Alaska went on to knock out establishment Republicans in primaries. In Nevada, Senate majority leader Harry Reid - who maneuvered to make sure Tea Party-backed Sharron Angle would be his opponent - edged out a very tough victory.

California proved the outlier, bucking the national trend by re-electing incumbent Democratic Sen. Barbara Boxer, but not without a strong challenge from Republican Carly Fiorina, who kept the race in California within the margin of error through most of the campaign and elevated her stature in the GOP.

Pelosi, elected in San Francisco in 1987, had become a national symbol of voter rage. That rage was particularly directed toward the swing-district Democrats she once recruited to build her Democratic majority in 2006.

The very achievements for which she was hailed as one of the most effective speakers in modern times - a huge health care overhaul, an $800 billion stimulus, climate-change legislation and a re-regulation of Wall Street - came to represent the overreach that independent voters rejected Tuesday.

More than anyone in Washington, it was Pelosi who delivered on President Obama's agenda. His plummeting popularity helped sink her, but she had become a near toxic figure in race after race, tied like an albatross to the necks of Democratic incumbents across the country. Without her, Obama will have to overhaul his legislative strategy. House Republicans, however, face both a Democratic Senate and a presidential veto that will sharply constrain their ability to enact their agenda.

Republican leader John Boehner, an 18-year Washington veteran from Ohio, is poised to take the gavel in January, promising "a new way forward" that will focus on cutting spending and renewing the Bush-era tax cuts. Those tax cuts are set to expire Dec. 31, forcing congressional action in a lame-duck session that will start Nov. 15.

This was the third election in a row in which voters rejected a large number of incumbents, a level of political volatility not seen since the 1950s. Republicans said they know the ugly mood holds peril for them too, despite their back-from-the-dead revival from a trouncing in 2008 and 2006.

Boehner has promised not to repeat the mistakes of his GOP predecessors, including deficit spending, but Republicans campaigned on generalities and have not yet made the specific and potentially unpopular choices that deficit reduction would require.

Pelosi has not yet said whether she will run again to lead Democrats in the minority. She is almost certain to be challenged. GOP Speakers Newt Gingrich and Denny Hastert retired shortly after similar election defeats.

Democrats told themselves that never again would they grow complacent or be taken by surprise, as they were in 1994 when Republicans took control of the House for the first time in 40 years.

Yet signs of voter unease emerged early in the Obama presidency, with polls consistently showing Obama's one weakness was worry about the sharp rise in deficit spending, even when he was riding high in overall popularity.

After the controversial stimulus was passed with no Republican votes in the House, Pelosi moved quickly to pass cap-and-trade climate-change legislation despite resistance from swing Democrats who feared they would suffer at the polls.

Obama then made health care reform the focus of his presidency, arguing that taming rising insurance costs would boost the economy and help workers hit by the recession. Pelosi dismissed grassroots resistance to the health care bill in August 2009, insisting that once it passed, it would prove popular. It has not.