With the outcome of a handful of House and Senate races still up in the air pending a recount or certified vote tally, here is a historical look at some of the nastiest and most protracted post-election Congressional fights. Many stretched into December, and some spilled into the next Congress. Rarely — at least in modern political history — has the person who was seated in January been removed after a successful election challenge.

1974
New Hampshire Senate
John Durkin (D) vs. Rep. Louis Wyman (R)

The initial result after Election Day showed Wyman won by 355 votes. But after the secretary of state counted the votes again, Durkin was deemed the winner by 10 votes. The certified results were then to be signed by the governor’s ballot commission. However, the commissioners, appointed by a Republican governor, investigated a couple of hundred ballots and determined Wyman was the winner by two votes. The Democratic-controlled Senate moved to decide the disputed points, but that effort was defeated by a filibuster threat from Sen. James Allen (D-Ala.). The disputed results then went back to New Hampshire, where it was decided there should be a do-over — a new election in September 1975 that Durkin won relatively easily. He was officially seated Sept. 18, 1975.

1984
Indiana’s 8th district
Rep. Frank McCloskey (D) vs. Richard McIntyre (R)

This contest in the “Bloody Eighth” remains one of the nastiest post-election battles in modern campaign history. At the end of the first count, a week after the election, McCloskey had a 72-vote lead. After reporting errors were discovered in two precincts, the tally showed McIntyre with a 34-vote lead. Without rechecking any other votes, the Republican secretary of state rushed the election certification to the governor’s office. Democrats protested after a recanvass of votes in another county put McCloskey ahead by 72 votes. The House, then controlled by Democrats, refused to seat either man. Republicans unsuccessfully argued for McIntyre to be seated while the outcome was investigated. In April 1985, a special House task force concluded after a recount that McCloskey had in fact won by four votes out of more than 233,000 cast. On May 1, 1985, the House voted to seat him.

1994
Connecticut’s 2nd district
Rep. Sam Gejdenson (D) vs. Ed Munster (R)

The initial vote showed Gejdenson ahead by two votes out of more than 186,000 cast. Recounts boosted his margin to four votes, and then, after a six-day hearing by the state Supreme Court, Gejdenson claimed a 21-vote margin of victory. House Republicans, still celebrating their historic wins and new majority, agreed to seat Gejdenson at the start of the new Congress, pending further review. Gejdenson had been a member of the House Administration panel that waded into the bloody post-election fight in Indiana’s 8th district in 1985, and some Republicans saw an opportunity for revenge. However, then-House Oversight Chairman Bill Thomas (R-Calif.) said the GOP would not “duplicate the Democrats’ way of stealing seats,” and a three-member task force was set up to look at the race. The investigation dragged on, and Munster announced on April 28, 1995, that he was dropping his challenge, as polls showed that voters were growing weary of the protracted fight and opposed a special election to settle the matter.

1996
Louisiana Senate
Mary Landrieu (D) vs. Woody Jenkins (R)

Landrieu was certified the winner of the contest by the Louisiana secretary of state (a Republican), winning by 5,788 votes. But Jenkins argued that massive vote fraud and a corrupt political organization in the state denied him victory. He filed a lawsuit claiming vote fraud but withdrew it and took his case to the Senate instead. In the meantime, Landrieu was seated by the Senate “without prejudice” to Jenkins’ challenge, but the Rules and Administration Committee appointed two outside counsels, one from each party, to look into Jenkins’ allegations. In April 1997, the GOP-controlled Rules panel voted 9-7 along party lines to expand the investigation, rebuffing the outside counsels’ recommendation of continuing with a “preliminary” and “limited” inquiry. Rules Chairman John Warner (R-Va.) appointed a Republican-dominated team of attorneys and continued to pursue the investigation even after several of Jenkins’ witnesses recanted their stories in the summer of 1997, further infuriating Democrats. The matter lasted 10 months into the new Congress, but by October, the investigation had been exhausted and the results were allowed to stand, despite several instances of voter fraud being cited in the committee’s findings.

1996
California’s 46th district
Loretta Sanchez (D) vs. Rep. Bob Dornan (R)

After Sanchez defeated the six-term Republican by 984 votes, Dornan — the implacable lawmaker known as “B-1 Bob” — went to fight the results. He argued that rampant voting by noncitizens altered the outcome of the race and took his case to the House contested elections task force, which issued subpoenas and promised a hearing in Orange County. By the spring of 1997, Dornan came up with proof that noncitizens had voted and argued that more than 1,700 illegal votes had been cast. Ultimately, a Congressional task force concluded there was concrete evidence that 748 illegal votes had been cast, not enough to throw Sanchez’s victory into doubt. House Democrats attempted to shut down the probe in late 1997, but it wasn’t until February 1998 that the investigation was finally halted, the case dismissed and the outcome upheld by the House.

2000
Minnesota’s 2nd district
Rep. David Minge (D) vs. Mark Kennedy (R)
After the initial count, Kennedy had a 155-vote lead and Minge refused to concede. A recount was under way when Minge asked for his challenge to be dropped. It was Dec. 12, 2000, the same day the U.S. Supreme Court ended the presidential recount in Florida. At the time, Kennedy’s lead stood at 148 votes, with 300 contested ballots left. But the 155-vote margin stood as the official tally because Minge dropped the recount challenge.

2000
Michigan’s 8th district
Dianne Byrum (D) vs. Mike Rogers (R)

Rogers’ 160-vote lead after Election Day had shrunk to a 152-vote lead by late November, at which time Byrum was able to seek a recount under state law. After a hand recount of 207 precincts failed to produce enough votes for Byrum to overcome Rogers’ lead, the Republican asked the Michigan secretary of state’s office to stop counting votes in mid-December. Byrum conceded on Dec. 15, 2000, when the unofficial gap between the candidates stood at 88 votes. The final margin was 111 votes, making it the closest House contest of 2000.

2006
Florida’s 13th district
Christine Jennings (D) vs. Vern Buchanan (R)

After a recount, Buchanan was certified the winner by 369 votes out of nearly 240,000 cast. Democrats cried foul, citing the more than 18,000 “undervotes” — ballots where voters registered their preference for other offices but not a choice in the Congressional race. Jennings’ campaign blamed a potential software glitch in touch-screen machines as well as a poor ballot design for the large undervote. However, post-election tests failed to provide conclusive evidence to back up her assertions. Jennings filed a state lawsuit and contested the election with the House Administration Committee. Buchanan was seated in January 2007, although Democrats withheld the right to remove him if Jennings succeeded in either of her challenges. A three-Member panel was named to investigate the dispute. A Government Accountability Office report issued in August 2007 said that no “smoking gun” had been found and that a deeper inquiry was needed to find the problem in the local election system. A final GAO report in February 2008 concluded that bad ballot design, not faulty electronic voting machines, was largely to blame for the large undervote, effectively ending Jennings’ challenge. Jennings ran against Buchanan again in 2008, losing by more than 65,000 votes.