In the 1980s and ’90s, a series of ethics scandals roiled Congress, claiming the careers of several influential politicians. Among them: House Speaker Jim Wright (D-Tex.), for accepting excessive speaking fees, and House Speaker Newt Gingrich, (R-Ga.), for misusing a tax-exempt foundation.

Badly bruised by the ethics fights, House lawmakers agreed to an informal cease-fire in 1997. The unspoken agreement to refrain from filing complaints held for seven years until 2004, when the House Ethics Committee reprimanded then-House Majority Leader Tom DeLay (R-Tex.) for misconduct.

But since then, ethics committees in the House and Senate have been loath to discipline their own, moving to censure or reprimand just two lawmakers for improperly using their offices: Rep. Charles B. Rangel (D-N.Y.) in 2010 and Rep. Laura Richardson (D-Calif.) in August. Letters of admonishment, a lesser punishment, have been sent out four times in the Senate. Sen. John Ensign (R-Nev.) resigned last year while under investigation by the Senate Ethics Committee.

The pattern has prompted critics to euphemistically call the panels “protection committees,” according to interviews with nearly a dozen ethics experts and government watchdog groups.

“The House Ethics Committee and the Senate Ethics Committee are structured in a way to protect incumbents rather than to discipline them,” said Craig Holman, a campaign finance and government ethics lobbyist for Public Citizen. “Members are overseeing each other, and they make sure that nothing comes back to haunt them.”

The chief counsel for the House committee declined to comment. The chairman and vice chairman of the Senate Ethics Committee, Barbara Boxer (D-Calif.) and Johnny Isakson (R-Ga.), said in a statement: “The committee’s record of serious and bipartisan investigations speaks for itself.”

Lawmakers also heavily on the committees for legal advice on a range of activities: accepting gifts, raising money or voting on legislation that might pose a conflict. Between 2007 and 2011, lawyers for the two committees sent at least 2,800 written opinions to lawmakers and provided e-mailed advice 6,500 times. Guidance has been given over the phone more than 40,000 times, records show.

The opinions are kept confidential, unless lawmakers choose to make them public. When they do, usually in response to challenges from political opponents or journalists, the released documents invariably support the actions the lawmakers had already taken.

Rep. Ken Calvert (R-Calif.), for instance, directed $1.2 million in tax dollars to expand the Corona Transit Center in his Southern California district. The center sits near seven rental properties the congressman owned.

After a report in the Los Angeles Times, Calvert sought an opinion in 2007 from the House Ethics Committee about the propriety of the earmarks. The committee ruled that any personal benefit to Calvert was “remote, inconsequential, or speculative.”

Calvert posted the opinion on his Web site under the headline: “Ethics Approval.”

Watchdog groups say the Calvert opinion and others like it have given lawmakers free reign to direct federal money to projects that coincide with their financial interests — as long as they and their families are not the only beneficiaries.

An in-depth, interactive look at the personal wealth of members of Congress - how they made it and how they handle their finances.

“These private opinions enable lawmakers to know where the ethics committee is going to draw the line and how far they can lean over that line,” said Steve Ellis, vice president of Taxpayers for Common Sense, a watchdog group that monitors Congress.

In February, The Washington Post reported that 33 lawmakers directed more than $300 million in earmarks and other spending provisions to public projects next to or within two miles of their own property. The Post also found that another 16 lawmakers directed tax money to companies, colleges or community programs where their spouses, children or parents worked or served on boards.

In many of the cases, the lawmakers told The Post that they had received permission for the spending measures from the ethics committees.

When Sen. Tim Johnson (D-S.D.) wanted to add millions to a Pentagon program his wife evaluated as a contract employee, Barbara Johnson told The Post that she called the Senate ethics committee to ensure the arrangement didn’t cross ethical lines. “They said it didn’t pose any conflict,” she said.

After the scandals involving DeLay and lobbyist Jack Abramoff, Congress took steps to make the process of investigating complaints more independent, creating the Office of Congressional Ethics. Designed as an in-depth investigative arm, the OCE has conducted a series of lengthy probes since its creation in 2008, referring its findings to the House Ethics Committee, which has the ultimate say on possible sanctions.

To date, the OCE has referred 32 cases of possible wrongdoing against lawmakers to the committee, which has levied no sanctions in 30 of the cases. The committee ordered Rep. Jean Schmidt (R-Ohio) to repay $500,000 worth of legal services she improperly accepted, and the panel decided to adopt an OCE report detailing travel expenses Rangel improperly took as an admonishment of the congressmen. Six additional cases are pending.

In the vast majority of the cases, the committee has exonerated the lawmakers and issued opinions that have had the effect of shielding other members of Congress from similar allegations, watchdog groups say.

In 2010, for instance, the OCE made a referral for an investigation involving three lawmakers who held fundraisers with representatives of Wall Street firms on the eve of voting on the Wall Street Reform and Consumer Protection Act of 2009. Reps. John Campbell (R-Calif.), Joseph Crowley (D-N.Y.) and Tom Price (R-Ga.) offered the financial industry representatives one-on-one meetings during the fundraisers.

The OCE found “substantial reason to believe” that the fundraisers were “linked to an official act.” But the House Ethics Committee disagreed. It ruled that the politicians had already staked out positions on the bill, and there was no interaction with their staff or discussions about the bill at the fundraisers.

Watchdog groups say the ruling served to relax the already loose standards on lawmakers who wish to raise money from individuals and corporations with business before Congress.

Today, watchdog groups worry that the OCE’s future may be in jeopardy. Members of the Congressional Black Caucus have tried to dismantle the panel, saying it has targeted a disproportionate number of African American lawmakers. Last year,Rep. Mel Watt (D-N.C.), a target himself who was ultimately exonerated by the House Ethics Committee, sponsored an amendment to cut the OCE’s budget by 40 percent.

His effort failed, but close to a quarter of the House backed his amendment.

Watchdog groups say they now fear that lawmakers will try a different tact this year by declining to appoint a new OCE board of directors. Board members decide which cases to investigate and which to refer to the House Ethics Committee. The terms of four of the eight board members are up at the end of the year.

Last month, eight government watchdog groups wrote to House Speaker John A. Boehner (R-Ohio) and Minority Leader Nancy Pelosi (D-Calif.), urging them to begin considering the replacements for the departing board members.

Boehner did not respond to requests for comment. A spokesman for Pelosi, Drew Hammill, said, “House Democrats are firmly committed to the continuation of the OCE, and replacements will be named at an appropriate time later this year.”

OCE Director Omar Ashmawy said he’s hopeful a new board will be named soon.

“I’m cautiously optimistic, but I’m going to be sweating it out,” he said. “I hope people will be paying attention.”