California 30: Rep. Brad Sherman (D) vs. Rep. Howard Berman (D)
One of the nastiest House races of 2012 was between two incumbent Democrats due to redistricting and the state's new primary system, in which the top two finishers advanced to the general election. Rep. Brad Sherman had at least one advantage over Rep. Howard Berman: He represented more of the redrawn Sherman Oaks-area district. Sherman won the primary with 42.4% of the vote compared with 32.4% for Berman. The remaining votes were split among five candidates. The race hit a nasty patch last month, when the two men shouted at each other at a public forum.
California 31: Rep. Gary Miller (R) vs. Bob Dutton (R)
Seven-term incumbent Rep. Gary Miller faced a tough challenge from a fellow Republican in a race also determined by California's new primary system. Miller's opponent is Bob Dutton, a state senator and businessman. Miller represented none of this redrawn district, while Dutton represented much of it in the state legislature.
California 36: Rep. Mary Bono Mack (R) vs. Raul Ruiz (D)
Rep. Mary Bono Mack, seeking an eighth full term in the House, was a frequent target of Democrats hoping to pick off a Republican in a Democratic district. This year, she found herself fending off a strong challenge from Democrat Raul Ruiz, a Mexican-American, Harvard-educated physician. But Bono Mack survived strong challenges before and has a moderate voting record. She also prevailed over Ruiz in her first one-on-one matchup, the June "top-two" primary in which they appeared together on the same ballot.
California 44: Rep. Laura Richardson (D) vs. Rep. Janice Hahn (D)
Redistricting forced another pair of Democratic incumbents to face off this November. Rep. Janice Hahn won a July 2011 special election to replace retiring Democratic Rep. Jane Harman. Rep. Laura Richardson was elected in a 2007 special election to replace the late Juanita Millender-McDonald. Hahn appeared to have an advantage due, in part, to an ongoing ethics saga for Richardson that resulted in a reprimand and $10,000 fine by the House Ethics Committee for campaign finance violations involving her congressional staff. Hahn also enjoyed a huge fundraising and cash-on-hand advantage at the start of October. Hahn trounced Richardson in the primary.
Florida 9: Former Rep. Alan Grayson (D) vs. Todd Long (R)
In just one term in Congress, Democrat Alan Grayson mastered the art of making headlines with his blunt and abrasive rhetorical style. During the debate over health care, he said the Republican health care plan was, "Don't get sick, and if you do get sick, die quickly." He also said on CNN that Republicans were "foot-dragging, knuckle-dragging Neanderthals." In a 2010 TV ad, he called his Republican opponent, Daniel Webster, "Taliban Dan." Although he quickly became a hero among liberals, Grayson went on to lose his bid for a second term by a staggering 18 points.
Grayson was running in a new district in the Orlando suburbs and his Republican opponent was Todd Long, an attorney, small businessman and conservative radio show host.
Florida 18: Rep. Allen West (R) vs. Patrick Murphy (D)
Rep. Allen West was a top target for Democrats The freshman Republican's sharp rhetoric during his first term did not endear him to colleagues across the aisle. For instance, West last summer e-mailed Democratic National Committee Chairman Rep. Debbie Wasserman Schultz that she was "the most vile, unprofessional and despicable member of the U.S. House of Representatives." West's Democratic opponent was Patrick Murphy, a businessman and executive with a construction firm.
Florida 26: Rep. David Rivera (R) vs. Joe Garcia (D)
The race in Florida's southernmost congressional district was a rematch of 2010, but the dynamics could not have been more different. Republican incumbent David Rivera was elected in the Republican wave two years ago. Democrat Joe Garcia, a former Miami-Dade County Democratic party chairman, lost by nine points. The key difference this time was that Rivera was dogged by scandal and ethics issues. The district is still Republican-friendly and Garcia entered the final stretch in better position than two years ago.
Georgia 12: Rep. John Barrow (D) vs. Lee Anderson (R)
Moderate Georgia Democratic Rep. John Barrow was reelected to a fifth term in the House on Tuesday, and is the last white male Democrat from the Deep South in the House of Representatives, CNN projects. The remaining Democratic congressmen from Louisiana, Mississippi, Alabama, South Carolina and Georgia are African-Americans.
The member of the "Blue Dog" Democrats, the group of fiscal conservatives in the House, has faced strong Republican challenges every cycle, and this year Republican Lee Anderson got 46% to Barrow's 54%. Both parties put considerable resources into the race.
Though Barrow survived this year, the ranks of moderate Democrats have dwindled in the House, and fellow blue dog Larry Kissell lost his race in North Carolina.
Barrow had been fighting for his political life in this heavily Republican district, which is far better than Republicans had expected would be the case when they drew the district's boundaries.
Illinois 2: Rep. Jesse Jackson Jr. (D) vs. Brian Woodworth (R)
Despite a lengthy absence from Capitol Hill due to illness, Democratic Congressman Jesse Jackson Jr. will easily hold on to his Illinois seat, CNN projects.
Jackson was projected to defeated handily GOP contender Brian Woodworth, an attorney and university professor. Woodworth had criticized Jackson during the campaign for leaving the district unrepresented.
The nine-term congressman has been away from Congress and largely out of the public eye since May. His office said in June that he was taking a leave of absence, and the Mayo Clinic disclosed in August that he was suffering from depression.
Jackson is being investigated in separate cases for possible financial and ethical improprieties.
The FBI and federal prosecutors in Washington are investigating Jackson for possible financial improprieties, according to a law enforcement official.
The House Ethics Committee is looking into allegations that, in 2008, Jackson or one of his associates offered to raise money for then-Illinois Gov. Rod Blagojevich in exchange for Jackson being appointed to the Senate seat vacated by Barack Obama.
Illinois 8: Rep. Joe Walsh (R) vs. Tammy Duckworth (D)
Freshman Republican Joe Walsh was high on the list of most endangered GOP incumbents. Walsh barely won his seat in 2010 and redistricting has made it more Democratic. He had the additional misfortune of running in a presidential election year when favorite son Barack Obama was heading the ticket for the other party. Walsh made headlines with a number of controversial statements, including his assertion that medical science has advanced to the point where abortions are never necessary to save a woman's life. Democrat Tammy Duckworth, a decorated Iraq war veteran, led in fundraising and entered the final stretch with an advantage.
Illinois 10: Rep. Robert Dold (R) vs. Brad Schneider (D)
Republican Robert Dold won this Democratic-friendly district in the Republican wave of 2010, replacing fellow Republican Mark Kirk, who ran for the U.S. Senate. The redrawn district is more Democrat-friendly, but Dold kept the race competitive. His Democratic opponent was businessman Brad Schneider, who emerged battered from a competitive primary. Dold entered the final month of the campaign with a huge cash advantage but Schneider has benefited from sizable TV ad buys from the national Democratic Party and from a pro-Democrat super PAC.
Iowa 3: Rep. Tom Latham (R) vs. Rep. Leonard Boswell (D)
Iowa was one of 10 states to lose seats in Congress because of redistricting, setting up a member-on-member showdown between two veteran lawmakers in a merged Des Moines-area district. Democrat Leonard Boswell represented much of this new district in the late 1990s. Republican Tom Latham had a fundraising advantage due in part to his friendship with Boehner. The cash advantage was apparent on the airwaves, where Latham outspent Boswell, even when counting the considerable assistance the Democrat received from his national party. Boswell is no stranger to tight races. He survived the Republican wave of 2010.
Iowa 4: Rep. Steve King (R) vs. Christie Vilsack (D)
Republican incumbent Steve King's bid for a sixth term in Congress was his toughest. King won re-election in his old western Iowa district with 66% of the vote in 2010, and he never dipped below 59% in any of his previous races. This year, he faced a new district and a tough new challenger in Democrat Christie Vilsack, Iowa's former first lady and the wife of U.S. Agriculture Secretary Tom Vilsack. The good news for King was that his enormous new district in the northwest part of the state comprises mostly counties won in 2008 by John McCain. King had a fundraising advantage over Vilsack. But Vilsack was the strongest candidate Democrats could have fielded.
Louisiana 3: Rep. Charles Boustany (R) vs. Rep. Jeff Landry (R)