Republican incumbent Charlie Bass faced Ann McLane Kuster. Kuster lost to Bass in the general election in 2010 but ran again, and outraised Bass, though they started October with roughly the same amount in the bank. The Democrat far outspent her opponent on the airwaves even though the national Republican Party invested funds on behalf of Bass.

New York 24: Rep. Ann Marie Buerkle (R) vs. Former Rep. Dan Maffei (D)

Rep. Ann Marie Buerkle was elected in the Republican wave of 2010 and had to defend her seat Tuesday from the man she defeated. Democrat Dan Maffei, a longtime Capitol Hill staffer, won this upstate New York district in 2008 after it had been in Republican hands for almost 30 years. He lost the seat to nurse and tea party favorite Buerkle in one of the closest House races that year. The two had been evenly matched in fundraising and TV ad spending. The district leans slight more Democratic.

North Carolina 7: Rep. Mike McIntyre (D) vs. David Rouzer (R)

Democratic Mike McIntyre ran a competitive race despite a newly redrawn district that skews heavily Republican. The Republican nominee was David Rouzer, a state senator. McIntyre, an eight-term incumbent, led in fundraising and kept even with ad spending by pro-Republican outside groups and the national Republican Party. Rouzer stayed off the airwaves. Like fellow southern Democrat John Barrow in Georgia, McIntyre showed strong signs of life in a district that appeared to have been drawn to end his career.

Ohio 9: Rep. Marcy Kaptur (D) vs. Samuel "Joe the Plumber" Wurzelbacher (R)

Samuel Wurzelbacher, better known as "Joe the Plumber," became a conservative icon in the 2008 presidential race when he challenged then-candidate Obama on tax policy at a campaign event. Republican John McCain even mentioned him during the third presidential debate. Four years later, Wurzelbacher was running for Congress in a quixotic race against 15-term incumbent Democrat Marcy Kaptur, who was a safe bet for re-election. Kaptur handily defeated fellow Democrat Dennis Kucinich in a primary earlier this year.

Ohio 16: Rep. Jim Renacci (R) vs. Rep. Betty Sutton (D)

Ohio's most competitive House race pitted freshman Republican incumbent Jim Renacci against three-term Democratic incumbent Betty Sutton. Since August, the two had benefited from about $2 million in ad spending on their behalf from parties and outside groups, while Renacci's campaign about doubled Sutton's campaign in ad spending. The merged district, located in northeastern Ohio near, but not including, Cleveland, Akron, and Canton, leaned Republican but the race was up for grabs.

Tennessee 4: Rep. Scott DesJarlais (R) vs. Eric Stewart (D)

Republican physician Scott DesJarlais was elected to Congress in the Republican wave of 2010, defeating Democratic Rep. Lincoln Davis. He was a safe bet for re-election until a recent revelation that he had pressured a girlfriend to have an abortion a decade ago. DesJarlais was separated from his wife at the time. The Democratic nominee was Eric Stewart, a state senator. He had begun making an issue of the incident but the impact on DesJarlais' campaign in this rural, conservative district was unclear.

Texas 23: Rep. Francisco Canseco (R) vs. Pete Gallego (D)

Republican Francisco "Quico" Canseco was one of many freshman members elected in the GOP wave of 2010 who found himself in a competitive race for a second term. Canseco was a wealthy commercial real estate developer when he won his third bid for this seat two years ago, defeating Democratic incumbent Ciro Rodriguez. After a legal battle over the redistricting process, Canseco ended up with a district slightly more Democratic -- President Obama carried it in 2008 with 51%, according to the Cook Political Report. The Democratic nominee was Pete Gallego, a state representative who defeated former Rep. Rodriguez in the primary. Hispanics make up 66% of voters.

Utah 4: Rep. Jim Matheson (D) vs. Mia Love (R)

As Utah's only Democratic member of Congress, Jim Matheson was used to close races. He barely squeaked by in 2010 with 50% of the vote. This year may have proved to be Matheson's toughest race yet. His Republican opponent was Mia Love, the mayor of Saratoga Springs who would become the first female African-American Republican to serve in Congress. Love is a rising star in the party and was given a prominent speaking role at this year's Republican National Convention. The two were evenly matched in fundraising.

Wisconsin 1: Rep. Paul Ryan (R) vs. Rob Zerban (D)

Being named Mitt Romney's vice presidential running mate did not affect Paul Ryan's chances at getting re-elected to the House. He was a safe bet for against Kenosha County Supervisor Rob Zerban.

Ryan was asked multiple times whether he was hedging his bets by running for re-election while also running for vice president, but the question was irrelevant. Ryan was tapped for the ticket after the deadline had passed to have his name removed from the House ballot. Vice President Joe Biden was in the same position in 2008.

Wisconsin 7: Rep. Sean Duffy (R) vs. Pat Kreitlow (D)

Rep. Sean Duffy was one of the higher-profile freshmen elected in the Republican wave of 2010. He was a former Ashland County district attorney and tea party favorite, but he was probably best known for his work as a professional lumberjack athlete and ESPN commentator and as a cast member on MTV's reality show "The Real World." This year he faced a tough challenge from Pat Kreitlow, a former state senator and former local TV news anchor. Redistricting gave Duffy a more-GOP-leaning district. He also enjoyed a financial advantage. Despite these advantages, this remained the most competitive House race in Wisconsin.