Republican candidates in a handful of the country's most competitive House races appear poised to knock off Democratic incumbents tonight, based on early returns in 39 states.
The GOP was projected to pick up seats in districts from Virginia to Indiana, where Democratic incumbents won narrowly in 2008 and John McCain carried the presidential vote.
Long-time Democratic Rep. Rick Boucher was projected to lose to his Republican opponent in Virginia's 9th congressional district, a sign many pundits say reflects a big GOP win in the making. Other competitive Virginia races appeared headed in the same direction.
In Virginia's fifth district first-term Democrat Tom Perriello is projected to fall to Republican challenger Robert Hurt, despite repeated campaign appearances on his behalf by President Obama.
In Indiana, two of three GOP candidates in the state's most competitive races are projected to defeat their Democratic incumbent opponents.
"If the Democrats lose two out of three tough races in Indiana they are going to lose the House," predicted George Stephanopoulos, ABC News' chief Washington correspondent and co-anchor of "Good Morning America."
And in South Carolina, voters are projected to send Republican Tim Scott to Congress, the first African American Republican member of the House since J.C. Watts was elected in 1994 and retired in 2003.
House Speaker Nancy Pelosi tonight rejected numerous polls predicting a Republican landslide among House candidates and defiantly predicted that Democrats will retain control of the House of Representatives.
"The early returns and overwhelming number of Democrats who are coming out – we're on pace to maintain a majority in the House of Representatives," Pelosi told reporters during a photo op in Washington.
Republicans need to win just 39 seats from Democrats to claim a 218-seat House majority, a feat ABC News' pre-election race ratings and many polls have shown to be easily within reach. More than 100 Democrat-held seats appeared vulnerable going into midterm Election Day, including 68 seats that either lean Republican or are toss-ups.
The last time Republicans took control of the House from Democrats in a 1994 avalanche -- the so-called Republican Revolution -- they flipped 52 seats.
A GOP victory would bring an end to the often embattled tenure of Speaker Pelosi, who made history in 2007 when she became the first woman to ever hold that rank, and force dozens of Democratic reps to hand over the gavels -- and the offices -- of their powerful committees to their Republican rivals.
It would also set the stage for Ohio Republican Congressman John Boehner, the son of a bar owner and one of 12 children who became president of a plastics company before entering politics, to become the next speaker.
A split balance of power in Congress would also make it much harder for President Obama and Democrats to advance their legislative agenda and increase the prospect of political gridlock on everything from taxes and spending to immigration.
The magnitude of the looming wave is hard to predict, given the number of competitive seats, lack of exit polling in many races and variability of voter turn out. But which party will control the House beginning in January will likely be known soon after polls close.
If Republicans seize a majority, as expected, it would be only the third time in 50 years that control of the House has changed hands, giving a resounding victory to the party that ceded power to Democrats four years ago.
Prospects of a GOP takeover in the Senate appear less likely, although Republicans are expected to make inroads in that chamber, as well.
Exit polling showed anxiety over the economy topped the list of voters' concerns Tuesday and compounded their near-record low approval of their government and the political parties, as seen in recent polls.
Democrats in traditionally blue districts appeared to be neck and neck with their Republican challengers based on early returns in a number of key races.
Iin the Democrat-dominant Virginia suburbs outside Washington, freshman Democrat Gerry Connolly has been under surprising pressure from a conservative businessman he defeated by 12 points in 2008. A Connolly defeat would signal a much broader and deeper wave for the GOP.
Meanwhile, in the district around Cincinnati, which sent Democrat Steve Driehaus to Congress two years ago, the same Ohio voters seem ready to send former seven-term Republican Rep. Steve Chabot back to Washington; a trend seen in a handful of other races across the country.
The strength of a coming Republican wave is also evident in a liberal corner of Hawaii, the state's first district, where 70 percent of voters supported Obama in 2008 but could now send a Republican to represent them in Congress in 2011.
A deep anti-incumbent, anti-establishment mood has also affected veteran Democrats and liberal icons in blue districts, some of who have been in the political fights of their lives, even if they are likely to eek out victories Tuesday.
Missouri Democrat Ike Skelton, who chairs the House Armed Services Committee, John Spratt of South Carolina, who chairs the House Budget Committee, and Jim Oberstar of Minnesota, who heads the House Transportation Committee, have each served more than two decades in Congress but have perhaps never faced a more vigorous reelection challenge.
Even Massachusetts' Barney Frank, one of the most prominent Democrats in the House, and John Dingell of Michigan, the longest-serving U.S. Representative in history, have been threatened by Republican challengers this year.
Mounting the challenges to Democratic incumbents across the country has been a colorful and diverse cast of Republican candidates that includes political rookies, grizzled veterans and Tea Party-backed conservatives.
They include a 28 year-old Republican rocket scientist in Arizona; an Emmy award-winning sportscaster in North Carolina; and a pizza parlor owner in Illinois, all who have kept their Democratic opponents playing defense.
In New York, Republican opthamologist Nan Hayworth is vowing to lead the charge for repeal of Democrats' health care law, while Arizona dentist Paul Gosar is running to oust incumbent Ann Kirkpatrick, who's reelection could hinge on support and turnout among Native Americans.
If the House falls under Republican control and Democrats maintain their hold on the Senate, it would be the first time in 80 years that one chamber has switched hands without the other.