Democratic victories in Pennsylvania helped the party pick up at least three of the 15 seats they needed to regain control of the House of Representatives as voters ousted a veteran Republican congressmen being investigated by the FBI and another who admitted an extramarital affair.

The Democratic tide pushed aside Rep. Curt Weldon, who saw the homes of friends and family raided in October, and Rep. Don Sherwood, whose affair became public when his ex-mistress filed a lawsuit alleging abuse. Both lost to political newcomers in Tuesday's election, as did three-term GOP incumbent Melissa Hart.

Two other GOP congressmen were locked in tight races Wednesday morning.

Check Your State, Check Your Race by clicking BALANCE OF POWER dropdown menu above.

With 93 percent of precincts reporting, Weldon's Democratic challenger, Joe Sestak, had 57 percent of the vote. Sherwood's Democratic opponent, Chris Carney, had 53 percent of the vote with 99 percent of precincts reporting.

Sherwood announced he was through with politics, while Weldon said it was time "to ride off into the sunset."

Democrats Patrick Murphy and Lois Murphy — who aren't related — held the slightest of leads in the final two unresolved races early Wednesday.

The candidates and outside groups spent about $40 million in the five races. Democrats got the bigger payoff, regaining the edge in the state's delegation for the first time since 1998.

Weldon, already in a tight race with Sestak, was dealt a severe blow when news broke that the FBI was investigating the 10-term incumbent to see if he used his influence to help his daughter's lobbying firm secure contracts from foreign clients.

"It just wasn't meant to be. The timing was not good. The mood in the country as you can see is sour," said Weldon, 59. "Rick Santorum went down big. Lynn Swann went down big. Some of my colleagues went down as well."

Sestak, a retired Navy vice admiral, thought that voters were focused on traditional pocketbook issues — jobs, health care and education — but said, "Iraq became almost a poster child for a government that had lost its way."

Sherwood, who represented a rural district in northeastern Pennsylvania for four terms, had one of the safest seats in Congress until last year when he admitted to a five-year extramarital affair with a woman 35 years his junior.

A 65-year-old married father of three, Sherwood was sued in 2005 by the woman, who alleged that he physically abused her throughout their affair. He agreed to pay her about $500,000 in a settlement last year.

Carney, a professor and lieutenant commander in the Navy Reserves who served as a military analyst at the Pentagon, used the affair to target Sherwood. The lawmaker countered with an ad in which he said he was "truly sorry" for cheating on his wife, but denied ever abusing his mistress.

Sherwood acknowledged that the affair helped do him in.

"I think the affair was a contributing factor. I'm not sure if it was the overriding factor," he said. "Overall, it was just a bad night for Republicans. I'm done with politics, but I'm not going away."

Hart lost to Jason Altmire, a health care executive who was helped by a television advertising blitz and visits from national Democratic leaders. The Pittsburgh-area district has more Democrats than Republicans, but voters supported Bush in the last presidential election.

Like other Democratic candidates, Altmire attacked his opponent for frequently voting with Bush.

Two-term Republican Rep. Jim Gerlach was in a close race with Lois Murphy, an attorney who almost beat him in 2004. With 94 percent of precincts reporting, he led Murphy by fewer than 2,100 votes among more than 227,000 ballots cast.

Gerlach planned to await the final tally at home, but said he was pleased by his campaign's turnout efforts. Murphy, as midnight approached without a decision, called it "deja vu all over again."

Commercials for the two candidates dominated Philadelphia-area television sets, with Gerlach trying to portray Murphy as a far-left liberal and Murphy trying to connect Gerlach with President Bush's more unpopular policies.

GOP Rep. Mike Fitzpatrick, a freshman, trailed Iraq war veteran Patrick Murphy as of Wednesday morning.

With 100 percent of precincts reporting, Murphy led by 1,500 votes among nearly 250,000 ballots cast. Provisional and overseas ballots remained uncounted as of Wednesday morning.

Fitzpatrick highlighted his role in bringing a planned veterans cemetery to Bucks County and in preserving green space. Murphy tried to focus on the war and Fitzpatrick's opposition to federal funding for stem cell research.

Democratic Rep. John Murtha, a decorated Vietnam veteran who a year ago became a leading opponent of the war in Iraq, easily defeated GOP challenger Diana Irey. Murtha has said he would run for House majority leader if Democrats take back the House.

In another race in suburban Philadelphia, Raj Peter Bhakta, a Republican and former contestant on NBC's "The Apprentice," lost his bid to oust Democratic Rep. Allyson Schwartz.

Click here to visit YOU DECIDE 2006, FOXNews.com's complete election center.