After a barrage of advertising as both parties sought control of Congress's two chambers, today's election is likely to confirm the status quo: the Republicans keep the House and Democrats narrowly control the Senate.
Voters will decide today who will occupy all 435 U.S. House seats and 33 of the 100 Senate seats. While Democrats' goal of wresting control of the House was long viewed as remote, Republicans early this year were given a good chance to win the four seats needed for a Senate majority. A crucial retirement, a primary loss and missteps by Republican candidates dimmed those prospects.
"The 113th Congress is going to be a carbon copy of the 112th," said Ross Baker, a professor at Rutgers University in New Brunswick, N.J., who specializes in American politics.
The next Congress, with either a second-term President Barack Obama or a new President Mitt Romney, will face divisive tax-and-spending issues after years of unsuccessfully trying to reduce the budget deficit. Lawmakers also may have to address the so-called fiscal cliff of tax increases and spending cuts that will start in January if Congress doesn't act in a lame- duck session beginning later this month.
Continued gridlock would be probable next year in a Congress with an unchanged balance of power, said Jennifer Duffy, Senate analyst for the nonpartisan Cook Political Report in Washington. Both parties will "find things in this election to encourage them to continue to behave as they've behaved the last two to four years," she said.
Congress's Gallup Poll approval rating was 21 percent in October, among the lowest historically in the month before an election.
In the House, campaign analysts predict that Democrats will gain at most 10 seats, far short of the 25 they need to win a majority. Redistricting after the 2010 Census favored Republicans in most areas. Some moderate Democrats decided to retire rather than seek re-election in Republican-leaning districts.
Democrats control the Senate 53-47. Republicans are defending 10 seats compared with 23 Democratic seats. Of those races, the Cook Political Report rated 10 as "toss-up," where neither party appear to have a clear advantage. The odds of a Republican Senate majority fell from 70 percent in February to less than 40 percent now, according to Cook.
The odds began declining when Republican Senator Olympia Snowe of Maine announced in February she would retire.
Missouri Senate candidate Todd Akin had been favored to defeat first-term Democratic Senator Claire McCaskill until August, when he said "legitimate rape" rarely causes pregnancy.
About two weeks before Election Day, Republican Richard Mourdock imperiled his Senate campaign in Indiana by saying pregnancies resulting from rape are "something God intended to happen." A favorite of the anti-tax tea party, Mourdock defeated six-term Republican incumbent Richard Lugar in a primary vote. Mourdock is running against Democrat Joe Donnelly, a three-term House member.
Of all the Senate battles, Virginia's may be the best indicator tonight of which party is running stronger nationally. The race between former governors Tim Kaine, a Democrat, and George Allen, a Republican, has mirrored the presidential campaign in polls.
"If Kaine is running ahead it will tell you several things, it may tell you the president is doing well," Baker said.
The top Senate races were flooded with advertising funded by outside partisan groups, including Virginia with $35 million, Wisconsin with $30.7 million, Ohio with $27 million and Indiana with $21.5 million, according to the nonpartisan Center for Responsive Politics in Washington.
The Massachusetts Senate race has been among the most closely watched. Incumbent Republican Scott Brown and Democrat Elizabeth Warren were in a tight race, though in the past several weeks she has pulled ahead. Warren gained star status in her party by attacking Wall Street, and Democrats gave her a prime-time speaking slot at their national convention in September.
Connecticut's Senate race pits three-term Representative Chris Murphy, a Democrat, against Linda McMahon, former president of World Wrestling Entertainment. She ran unsuccessfully for the Senate in 2010 and has spent almost $100 million of her own money on her two campaigns.
In Arizona, six-term Republican U.S. Representative Jeff Flake is running for retiring Senator Jon Kyl's seat. Flake is in a close race with Democrat Richard Carmona, who was U.S. surgeon general during the George W. Bush administration.
Nevada Senator Dean Heller, appointed in 2011 to fill a vacant seat, is running neck-and-neck with Democratic U.S. Representative Shelley Berkley.
In Nebraska, Republican Deb Fischer is rated by Cook and others as likely to win retiring Democrat Ben Nelson's seat. That may be offset in Maine, where independent Angus King, a former governor, is running ahead of the Republican and Democratic nominees for Snowe's seat. King probably would caucus with Democrats.
Two other Senate seats Republicans sought to pick up proved a challenge. In Montana, the race between Senator Jon Tester, a Democrat, and Republican U.S. Representative Denny Rehberg is close. In North Dakota, former state Attorney General Heidi Heitkamp, a Democrat, was tied with freshman Republican Representative Rick Berg in an Oct. 3-5 Mason-Dixon poll.
In the House, Republican lawmakers in many states were able to draw congressional voting districts in their favor, said political scientist David Rohde of Duke University in Durham, North Carolina. Without redistricting, Democrats probably would gain 11 to 20 seats instead of one to nine, he said.
Veteran Republican Representative Steve King of Iowa faced the toughest re-election fight of his career. King, a five-term congressman, is opposed by Democrat Christie Vilsack, Iowa's former first lady and wife of U.S. Agriculture Secretary Tom Vilsack. She received campaign support from former President Bill Clinton.
Democratic Representative Jim Matheson of Utah, a leader of the fiscally conservative Blue Dog Coalition, is running against Republican Mia Love, the mayor of Saratoga Springs, Utah. If she wins, Love would be the first black woman to serve as a House Republican.
In Florida, tea party-backed freshman Allen West, a Republican, was in a tight race with Democratic challenger Patrick Murphy. Outside groups allied with both parties have spent $5.3 million on the campaign.
Non-partisan redistricting in California and the state's universal primary law pitted incumbent House Democrats Brad Sherman and Howard Berman against each other in a Los Angeles- area district. Berman, the top Democrat on the House Foreign Affairs Committee, won the endorsement of second-ranking House Democrat Steny Hoyer of Maryland.
Redistricting in California could endanger House re- election bids by Republicans Dan Lungren, Brian Bilbray and Jeff Denham.
Senate Minority Leader Mitch McConnell of Kentucky has said that if his Republican Party wins control of the chamber, a priority would be repealing Obama's 2010 health-care law. Tax increases would be off the table as part of any plan to reduce the deficit.
If Romney wins the presidency, McConnell said he would urge him to immediately impose a moratorium on federal regulations. He's pushing for an end to what opponents call Obama's "war on coal."
With assistance from James Rowley and Roxana Tiron in Washington.