Kennedy is the 32-year-old grandson of slain Sen. Robert Kennedy of New York. His great-uncles are the late President John F. Kennedy and long-time Sen. Ted Kennedy, D-Massachusetts, who died in office in 2009.
Joe Kennedy's second cousin, Democratic Rep. Patrick Kennedy of Rhode Island, left office in January 2011, ending his family's 64-year streak of service in the U.S. Congress.
Joe Kennedy is a former prosecutor and Peace Corps member; Bielat is a businessman and Marine Corps reservist.
Massachusetts 6: Rep. John Tierney (D) vs. Richard Tisei (R)
Rep. John Tierney, an eight-term incumbent, won re-election, CNN projected, despite being dogged by a financial scandal involving his wife and her brothers and an illegal gambling operation.
Minnesota 6: Rep. Michele Bachmann (R) vs. Jim Graves (D)
Tea party favorite Michele Bachmann won re-election, CNN projected. She was considered a shoo-in for re-election when she folded up her presidential campaign in January. Ten months later, Bachmann still had the advantage but she faced a tough challenger in Jim Graves, a wealthy businessman. Graves waged a competitive race in October, spending $1.2 million in TV ads, compared with $1.7 million for Bachmann. The conservative congresswoman had never posted huge numbers on Election Night, but redistricting made her district slightly more Republican.
Nevada 4: Steven Horsford (D) vs. Danny Tarkanian (R)
New district
Democrat Steven Horsford, the state senate majority leader, bested Republican Danny Tarkanian, a businessman and son of UNLV basketball coaching legend Jerry Tarkanian.
New Hampshire 1: Rep. Frank Guinta (R) vs. former Rep. Carol Shea-Porter (D)
Republican Frank Guinta lost to Democrat Carol Shea-Porter in the battle for New Hampshire's 1st Congressional District. Shea-Porter was elected in the Democratic wave of 2006 and served two terms before losing to Guinta in 2010.
New Hampshire 2: Rep. Charlie Bass (R) vs. Ann McLane Kuster (D)
Republican incumbent Charlie Bass lost to Ann McLane Kuster. Kuster had lost to Bass in the general election in 2010 but ran again and outraised Bass. 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 lost on Tuesday to the man she defeated two years ago. 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 in 2010. The two had been evenly matched in fund-raising and TV ad spending. The district leans slight more Democratic.
North Carolina 7: Rep. Mike McIntyre (D) vs. David Rouzer (R)
Democrat 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 fund-raising 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. A winner has not been yet projected.
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. But four years later, Wurzelbacher's run for Congress was foiled by 15-term incumbent Democrat Marcy Kaptur.
Ohio 16: Rep. Jim Renacci (R) vs. Rep. Betty Sutton (D)
In Ohio's most competitive House race, freshman Republican incumbent Jim Renacci beat three-term Democratic incumbent Betty Sutton. The merged district -- located in northeastern Ohio near, but not including, Cleveland, Akron, and Canton -- leaned Republican.
Tennessee 4: Rep. Scott DesJarlais (R) vs. Eric Stewart (D)
Republican physician Scott DesJarlais, who was elected to Congress in the Republican wave of 2010, won a second term despite the recent revelation that he had pressured a girlfriend to have an abortion a decade ago. DesJarlais was separated from his wife at the time.
Texas 23: Rep. Francisco Canseco (R) vs. Pete Gallego (D)
Republican Francisco "Quico" Canseco was one of several freshman members elected in the GOP wave of 2010 who lost in his bid 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 winner was Democrat Pete Gallego, a state representative.
Utah 4: Rep. Jim Matheson (D) vs. Mia Love (R)
As Utah's only Democratic member of Congress, Jim Matheson beat his Republican opponent, Mia Love, the mayor of Saratoga Springs, who would have become the first female African-American Republican to serve in Congress.
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 won handily against Kenosha County Supervisor Rob Zerban.
Wisconsin 7: Rep. Sean Duffy (R) vs. Pat Kreitlow (D)
Rep. Sean Duffy 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." He defeated a tough challenge from Pat Kreitlow, a former state senator and former local TV news anchor. Redistricting had given Duffy a more GOP-leaning district. He also enjoyed a financial advantage.
