Updated from 3:38 a.m. EST
Democrats won back control of the House of Representatives and appeared to be one Virginia recount away from ousting the Republican majority in the Senate.
Democrats had gained at least 27 Congressional seats from Republicans, giving them well more than the 218 seats necessary for a house majority that will likely ring in California Rep. Nancy Pelosi as the next House speaker.
In the Senate, Democrats had picked up five seats: Sherrod Brown defeated Republican Sen. Mike DeWine in Ohio, and Bob Casey Jr. will be the next senator from Pennsylvania, taking the seat currently held by the GOP's Rick Santorum.
In Rhode Island, Democrat Sheldon Whitehouse beat incumbent Lincoln Chafee, a centrist Republican, while in Missouri, Republican incumbent Sen. Jim Talent lost to Democrat Claire McCaskill.
And in a closely contested race in Montana, the
had just declared Democrat Jon Tester the winner over incumbent Conrad Burns.
Joe Lieberman, who ran as an independent in Connecticut after falling in the Democratic primary, is on his way back to the Senate after Ned Lamont conceded. Lieberman has said he will caucus with the Democrats if he secures the election.
To control the Senate, six Republican-occupied seats would have to give way to Democrats. With five of those seats now lost by Republicans, attention turned to a very tight race in Virginia, where Republican Sen. George Allen of Virginia trailed Democrat Jim Webb by fewer than 7,000 votes out of more than 2.3 million cast.
Regardless of the initial count in Virginia, a recount would likely be in the offing as state law allows a candidate who finishes half a percentage point or less behind to request a recount paid for by state and local governments.
Ahead of the election, many political analysts thought the Democrats had a good chance to take the House, but they were far less certain on what would happen in the Senate.
Democrats had been hoping that voter dissatisfaction with the Bush administration and the war in Iraq would return the House of Representatives to their hands for the first time in 12 years.
That displeasure seemed to work out for Democrats on Tuesday night.
reported that about 6 in 10 voters said in polling surveys that they disapproved of the way Bush was handling his job, and roughly the same percentage opposed the war in Iraq. Those who said they were unhappy were more inclined to vote for Democratic candidates than for Republicans.
Later Wednesday, media outlets were reporting that embattled Secretary of Defense Donald Rumsfeld had informed Republican officials that he would step down from office.
The GOP has held the House since 1994. That year, a group of Republicans led by Georgia's Newt Gingrich ran a campaign heavily opposed to then-President Bill Clinton and swept into control for the first time in 40 years with a platform they called the Contract With America.
As polls opened, all 435 seats in the House were up for election along with 33 Senate posts. At the same time, numerous governorships and hundreds of local contests were being decided.
Democrats also were doing well Tuesday in those governor's races, with the latest projections showing a pick-up of six seats in the 36 being contested. All but one of the additions by Democrats so far were in races without a Republican incumbent, although
was projecting Maryland Gov. Robert Ehrlich would be defeated by Democratic challenger Martin O'Malley.
In Minnesota, incumbent Republican Gov. Tim Pawlenty was in a tight race with Democrat Mike Hatch.
In New York, Attorney General Eliot Spitzer was well on his way to a landslide in the governor's race over Republican John Faso.
Bucking the down night by Republican gubernatorial candidates was California Gov. Arnold Schwarzenegger, who easily coasted to re-election over Democratic challenger Phil Angiledes.
Angiledes was long thought to have been trailing the seven-time Mr. Olympia in the polls, shifting much of the statewide electoral focus to various ballot measures.
Two of the most contentious propositions - one calling for a tax on state oil producers to fund alternative energy research, and another to add a $2.60-per-pack tax on cigarettes - were headed for defeat in recent returns.
California also saw the return to state politics of former Gov. Jerry Brown, who was elected attorney general.
Throughout the day, scattered reports of problems with ballots and voting machines emerged.
In one bizarre incident in Kentucky, a voting-site worker was accused of choking and shoving a voter, the
reported. According to the report, the voter didn't want to pick a candidate in a local election, but the poll worker said it was required, and ultimately a scuffle broke out.