In New York, another controversial race dominated by scandals, Tea Party-backed Carl Paladino is also projected to lose to Democratic Attorney General Andrew Cuomo.
Democrats have so far held on to their Senate seats in California, West Virginia, Hawaii, Maryland, Delaware, New York, Connecticut, Vermont and Oregon. The reigning party will maintain its majority in the Senate but leaders will lose their comfortable hold on the chamber, making it even more difficult to pass legislation on which there is little bipartisan compromise, such as energy and jobs.
Democrats gained a key victory in West Virginia, where Gov. Joe Manchin is projected to win, and in Connecticut, where Richard Blumenthal is projected to defeat World Wrestling Entertainment's Linda McMahon. While 88 percent were worried about the economy in Connecticut, they didn't take it out on the Democrat as voters did elsewhere; he won these voters by 54 to 45 percent.
Preliminary exit polls show strong discontent against President Obama in red states and even a surprising number in his home state of Illinois, where 48 percent disapprove of the president's performance, compared with 51 percent who approve of him. Voters have been hard hit by the economy, with four in 10 saying someone in their household has lost a job or been laid off in the past two years, higher than the three in 10 nationally who say the same.
Obama carried Colorado with 53 percent of the vote in 2008; fewer of voters now, 47 percent, approve of the job he is doing as president.
Older voters have voted for the Democratic candidate in each of the past three Senate races, including voting for Feingold in 2004 by a 14-point margin, but not this time. Those age 65 and older went for Johnson, 54-46 percent.
In Kentucky, 52 percent of voters said Paul's views were too extreme but the libertarian-leaning ophthalmologist won on the back of strong anti-President Obama sentiment in the state. By a 23-point margin, voters there said they were casting their ballots in opposition to Obama, with 62 percent disapproving of Obama's job performance overall, according to ABC News exit polls.
The sentiment was similar in West Virginia, which has voted Republican in the last three presidential elections. Seven in 10 disapprove of Obama's job performance, with approval at 30 percent. Nearly half of West Virginia voters said their vote was to express opposition to Obama, while far fewer -- 14 percent -- said they voted to express support for the president.
"Will the president take a lesson away from tonight?" House Tea Party caucus founder Michele Bachmann said on ABC News Now. "This is a profound repudiation of his policies."
Across the country, Senate incumbents, especially Democrats, were fighting for their political lives today, hoping to withstand Tea Party momentum and an election that has morphed into a referendum on Washington.
Democrats currently hold 59 seats in the Senate, Republicans 41. There were 37 seats in play, and the GOP needed an additional 10 seats to regain control.
In one of the most high-profile and anticipated races of the night, Reid defeated Angle, a Tea Party favorite.