It is still early, but ABC News projections so far show Democrats having a good night.
They have now netted three of the six seats they need to take a majority in the Senate -- and the projections so far show no Democratic Senate incumbents who stand to lose.
In the House, Democrats have gained seven of the 15 seats they need to take control.
And in gubernatorial races, projections show they have taken four seats from Republicans.
The newest results:
RHODE ISLAND: In a close Senate race, ABC News projects that Democrat Sheldon Whitehouse will defeat the Republican incumbent, Sen. Lincoln Chafee. Chafee had distanced himself from the Bush White House, and exit polls show that 62 percent of Rhode Islanders approved of his performance -- but in a heavily Democratic state, people were voting for change. Sixty-three percent of those polled said they wanted the Democrats to win control of the U.S. Senate.
OHIO: We project that Democrat Sherrod Brown will unseat incumbent Republican Sen. Mike DeWine. Exit polls show this race was largely a referendum on President Bush's leadership: Six in 10 voters there disapproved of the president's performance -- and of those, more than 85 percent voted Democratic in the Senate race.
In Ohio's gubernatorial race, Democrat Ted Strickland appears to have beaten Republican Kenneth Blackwell in an open contest. This was a governorship that had been in Republican hands.
PENNSYLVANIA: ABC News projects that Democrat Robert Casey will win over incumbent Sen. Rick Santorum, the No. 3 person in the Senate's Republican leadership. Exit polls show that Casey's win, like Brown's in Ohio, was the product of a disgruntled Pennsylvania electorate, dissatisfied over the conduct of the Iraq War.
CONNECTICUT: Sen. Joe Lieberman, running as an Independent, defeated Democratic challenger Ned Lamont -- even though Lamont had beaten him in the Democratic primary. Lieberman has vowed to vote with the Democrats in the Senate.
NEW JERSEY: We project that Democratic Sen. Robert Menandez will win over Republican challenger Thomas Kean Jr. This was a close, hard-fought campaign, and one that Democratic managers said they had to hold if they had hopes of winning a majority in the Senate.
FLORIDA: Incumbent Democratic Sen. Bill Nelson appears to have beaten Republican Katherine Harris -- the woman who, as Florida's secretary of state in 2000, presided over the tumultuous recount of votes in the presidential race between George W. Bush and Al Gore.
INDIANA: In raw vote counts -- not projections based on exit polls -- Democrats are ahead in three House seats currently held by Republicans. Meanwhile, in the Senate there, incumbent Richard Lugar is projected to beat Libertarian challenger Steve Osborn.
MARYLAND: The governor's seat changes hands here -- ABC News projects that Democrat Martin O'Malley has unseated Republican incumbent Gov. Robert Ehrlich.
In other races, where polls had not shown races to be close, incumbents so far were keeping their seats.
NEW YORK: Sen. Hillary Rodham Clinton -- the former first lady, widely touted as a contender for president in 2008 -- is projected to have won against Republican John Spencer.
MISSISSIPPI: Republican Sen. Trent Lott keeps his seat, defeating Democrat Erik Fleming.
MASSACHUSETTS: Sen. Ted Kennedy beat back a challenge from Republican Ken Chase.
MAINE: Republican incumbent Sen. Olympia Snowe appears to have kept her seat against Democrat Jean Hay Bright.