WASHINGTON President Barack Obama's Democrats will keep control of the U.S. Senate, media projected on Tuesday.
Republicans were projected to take control of the House of Representatives, but the Democrats would retain a slimmer majority in the Senate.
Here are results from some key races:
Democrat Joe Manchin won the Senate race in West Virginia, beating back a late surge by Republican rival John Raese. Manchin, the state's governor, won after distancing himself from Obama's healthcare overhaul and climate change legislation plans, winning support from the state's powerful coal industry.
Republican Marco Rubio, backed by the Tea Party movement, won the Senate race in Florida, beating Governor Charlie Crist, who ran as an independent, and Democrat Kendrick Meek. Rubio, a Cuban American and former state lawmaker, won the Republican primary over Crist because he was considered more conservative.
Republican Rand Paul, a Tea Party favorite, won a Senate seat in Kentucky over Democrat Jack Conway. The victory preserved a Republican Senate seat that Democrats had hoped to win.
Republican Dan Coats won the Senate race in Indiana over Democrat Brad Ellsworth. The victory by Coats, who retired previously from the Senate and had been working as a lobbyist, helped Republicans narrow the gap in the Senate.
Three-term Senator Russ Feingold lost his re-election bid in Wisconsin to Republican Ron Johnson, adding another seat to Republican gains in the chamber. Feingold, one of the most liberal members of the Senate, had trailed much of the race.
Republican Mark Kirk won the Illinois seat formerly held by Obama in the Senate. The loss by the Democratic treasurer Alexi Giannoulias was an embarrassment to Obama and his party in a state that typically leans Democratic. The president campaigned there in the final days of the race.
Republican Pat Toomey won a Senate race in Pennsylvania over Democrat Joe Sestak. Toomey, a fiscal conservative who had the backing of the Tea Party, led for much of the race and hit Sestak hard over the struggling economy in a state that was once dominated by industrial manufacturers.
California Democratic Senator Barbara Boxer, one of the more powerful liberals in the Senate, won re-election. She eked out the victory after a bruising battle against former Hewlett-Packard chief executive Carly Fiorina and with help from Obama.
Republicans captured another Democratic Senate seat, with North Dakota Governor John Hoeven beating Democrat Tracy Potter in the race to replace retiring Democratic Senator Byron Dorgan.
Republicans picked up a key Senate seat in Arkansas with Representative John Boozman defeating incumbent Democratic Senator Blanche Lincoln. Lincoln had been considered one of the most vulnerable Democratic senators in the race because of her support for President Obama's healthcare overhaul.
Connecticut Attorney General Richard Blumenthal won the state's Senate seat over Republican Linda McMahon. The close race was to replace retiring Democratic Senator Christopher Dodd. McMahon spent millions of dollars of the fortune she made while heading the World Wrestling Entertainment company.
Missouri Democratic Representative Ike Skelton, chairman of the House Armed Services Committee, lost his re-election bid to Vicky Hartzler, a former state lawmaker who attacked Skelton for his support of legislation Democrats pushed through to try to control climate change.
Democratic Representative Barney Frank, one of the most liberal lawmakers and co-author of the new controversial financial regulation law, easily won re-election after a bitter campaign. Frank beat Republican Sean Bielat, a U.S. Marine Corps veteran and business consultant, who had pounded Frank about billions of dollars in federal aid given to government sponsored mortgage companies Fannie Mae and Freddie Mac.
Florida Democratic Representative Alan Grayson lost re-election. Grayson had gained prominence when he described the Republican alternative proposal to healthcare reform as "don't get sick, and if you do get sick, die quickly," making him a big target of conservative activists.
Virginia Democratic Representative Tom Perriello lost his re-election bid despite a last-minute campaign rally with Obama. Perriello, who backed the massive economic stimulus package and the healthcare overhaul law, lost to Republican Robert Hurt, a Virginia state senator.
South Carolina Democrat John Spratt, head of the House Budget Committee, lost his re-election bid. Spratt served 27 years in the House of Representatives and rose to lead the powerful committee which sets annual spending priorities. He lost to Republican Mick Mulvaney, a state lawmaker who received strong backing from national Republican organizations.
Virginia Democratic Representative Rick Boucher lost his re-election bid to Republican state lawmaker Morgan Griffith. Boucher represents a conservative part of Virginia and voted against the healthcare legislation but backed the stimulus package aimed at reviving the struggling economy.
Republican John Kasich ousted Ohio Democratic Governor Ted Strickland, winning in a state that has been hit hard by the recession and will be a major battleground in the 2012 presidential election.
California elected Jerry Brown as governor again, showing residents preferred the 72-year-old who ran the state in the 1970s and 1980s over billionaire businesswoman Meg Whitman. Whitman, former eBay chief executive, poured more than $140 million of her own fortune into her first run for office.
Republican Governor Rick Perry of Texas defeated Democratic challenger Bill White, setting the stage for a showdown with the Obama administration over federal carbon dioxide limits. Perry, a conservative Tea Party darling and the state's longest-serving governor, won an unprecedented third term in the second most populous U.S. state.
(Compiled by Emily Stephenson; editing by Chris Wilson)