Washington Democrats, seizing on voter unrest over the Iraq war, defeated incumbent Republicans in Ohio and Pennsylvania on Tuesday in a bid to take control of the Senate.
In Pennsylvania, Democrat Bob Casey, son of a popular former governor, defeated incumbent Sen. Rick Santorum, a conservative and third-ranking member of the Senate GOP leadership. Democratic Rep. Sherrod Brown beat GOP incumbent Mike DeWine in Ohio, a state where Republican scandals was devastating for the party.
Democrats needed to pick off at least four more Republicans from among competitive races in Virginia, Tennessee, Montana, Missouri and Rhode Island to capture a Senate majority
Sen. Joseph Lieberman, the Democrats' vice presidential candidate in 2000 but running as an independent after losing the Democratic primary, kept his seat from Connecticut.
In New Jersey, Sen. Bob Menendez held off a strong challenge from Republican Tom Kean Jr., son of a former governor, to keep the seat in Democratic hands. Menendez had been viewed as the most vulnerable of 17 Senate Democrats seeking re-election.
Former First Lady Hillary Rodham Clinton, considering a Democratic bid for the White House in 2008, easily won re-election to a second term from New York.
Lieberman will be one of two independents in the new Senate. Rep. Bernie Sanders, an eight-terms congressman who calls himself a socialist, won the seat of retiring Sen. Jim Jeffords, also an independent. Both Lieberman and Sanders have said they will align themselves with Democrats.
Democrats also kept seats in Wisconsin, North Dakota, New Mexico, Michigan, Nebraska, West Virginia, Massachusetts, Florida, Delaware, Wisconsin.
Republicans won re-election in Indiana, Maine, Mississippi, Wyoming and Texas.
In Florida, Democratic Sen. Bill Nelson handily rebuffed a challenge from Republican Rep. Katherine Harris, a two-term House member.
Harris came to national attention in 2000 when, as Florida secretary of state, she certified Bush as the Florida winner in his nearly deadlocked presidential race with Democrat Al Gore. More recently, however, she fell out of favor with Florida Republicans, and was even urged by Florida Gov. Jeb Bush, the president's brother, not to run.
Democrats needed a net gain of six seats to take control of the Senate, which, except for a 19-month period in 2001 and 2002, has been run by Republicans since 1995.
Exit polls showed that almost six in ten voters disapproved of the war in Iraq, and an equal percentage said they disapproved of how President Bush was handling his job.
"We're not breaking out the champaign bottles yet. It's going to be a long night, but so far, so good," New York Sen. Chuck Schumer, chairman of the Senate Democrats' campaign operation, told supporters.
Amy Klobuchar, a prosecutor, kept the seat of retiring Sen. Mark Dayton in Minnesota in Democratic hands, defeating Republican Rep. Mark Kennedy.