Democrats, too, faced ethics accusations, among them Sen. Robert Menendez, who was reelected in New Jersey but whose lease deal with a federally funded antipoverty program raised conflict-of-interest questions.
But with Republicans in control of both houses, the ethics issue likely damaged them more.
Throughout the congressional campaign, Democrats accused the Republican leadership of permitting a culture of corruption to flourish on Capitol Hill, and the accusations seemed to resonate with voters, who in exit polls called the issue one of their top concerns.
It could come back to plague the Democrats in 2008 if they fail to act on their pledge to create a more honest government.
"I think there is pressure on them," said Richard Semiatin, an assistant professor of political science at American University in Washington. "There may not be immediate consequences, but there will be consequences two years from now," when they are up for reelection.
Semiatin likens the situation to George H.W. Bush's 1988 "read my lips" pledge not to raise taxes, which he broke after becoming president.
Semiatin said the Democrats might also get some support from conservative Republicans on issues such as reforming earmarks, special-interest funding bills that often benefit groups or companies that contribute heavily to members.
House Speaker-elect Nancy Pelosi has promised to take up ethics legislation within the first four days of her speakership. The House Democrats' ethics proposals likely will stick closely to a bill Pelosi introduced this year that called for a ban on privately funded travel and tighter controls on when retired members of Congress can lobby their former colleagues, say those involved in drafting the legislation.
Pelosi's bill also called for increased disclosure of earmarks, and it would limit the time allotted for floor votes, a reaction to the Republican leadership's decision in 2003 to allow the vote on Medicare prescription-drug legislation to go on for hours, as they hustled to get votes.
Jennifer Crider, a Pelosi spokeswoman, said several ethics changes that could be accomplished with simple rules changes, such as a ban on all gifts from lobbyists to members, might be taken up immediately.
More complex proposals, such as extending the current ban on lobbying for retired members from one year to two years after they leave office, would probably take longer, she said.
"Democrats throughout the last several years have really focused on this; we said that if we were entrusted with the majority what we would do is bring civility, honesty and integrity and fiscal discipline back to the House," Crider said. "So if you voted [for Democrats] in this last election, that is what you would want a Democratically controlled Congress to do."
Republicans, who have controlled both houses of Congress for most of 12 years, have been beset with ethics scandals since 2004.
Former House Majority Leader Tom DeLay was indicted by a Texas grand jury on charges that he broke campaign-finance law.
He also became embroiled in the scandal surrounding Jack Abramoff, the convicted Washington lobbyist who spread campaign donations, privately funded trips, restaurant meals and other gifts among members as he pushed for legislation to benefit his clients. Abramoff, who pleaded guilty in January to charges of defrauding Indian tribes he had represented and corrupting public officials, is cooperating with a Justice Department investigation focusing on a half dozen or more members of Congress.
Jim Manley, a spokesman for incoming Majority Leader Harry Reid of Nevada, said the Senate would wait until the House passes its ethics legislation before acting on its own package, which is similar to the House bill.
Neither measure includes a plan for creating more independent ethics panels in the House and Senate, a centerpiece of proposals favored by Washington-based watchdog groups, such as Public Citizen.
The group's Craig Holman, an ethics specialist, said that given the election results, the climate in Washington was more favorable for stronger ethics rules than at any time in the last decade. He said he expected the ban on privately funded travel would pass, along with lengthening the period during which former members of Congress may not lobby.
"Exit polls show that this was the most important issue for voters," Holman said. "The climate is very good now for some meaningful lobbying legislation."
Contact staff writer Chris Mondics at 202-408-2720 or firstname.lastname@example.org.
Chellie Pingree, president and chief executive of the nonprofit advocacy group Common Cause, will answer questions about ethics reform at http://go.philly.com/commoncause