In an interview Tuesday on “Kudlow and Company” on CNBC, Mr. Romney could not distance himself fast enough. “Once again, we’ve found people in Washington have not lived up to the level of respect and dignity that we would expect for somebody that gets elected to a position of high influence,” Mr. Romney said. “Very disappointing. He’s no longer associated with my campaign, as you can imagine.”

Republicans, of course, do not have an exclusive hold on scandal. As Democrats accused Republicans of engaging in a “culture of corruption” during the 2006 midterm elections, Republicans eagerly put the spotlight on Representative William J. Jefferson, the Louisiana Democrat who stashed $90,000 in his freezer — ill-gotten gains, the authorities said.

Still, there is a sort of “here we go again” sense among Republicans these days, especially since news of the Craig arrest broke on Monday afternoon. It is tough enough being in the minority, weighed down by the burden of the war in Iraq. Now Republicans have an even more pressing task: keeping their party from being portrayed not just as hypocritical and out of touch with the values of people they represent, but also as a laughingstock — amid headlines like “Senator’s Bathroom Bust,” which ran all Tuesday afternoon on CNN. The story also ran at the top of all the network evening newscasts on Tuesday.

“I’m hoping it’s a big mistake,” said one of Mr. Craig’s Republican colleagues, Senator Lamar Alexander, traveling Tuesday in Tennessee, his home state. “But it certainly does nothing to increase confidence in the United States Senate.”

With President Bush hobbled by his own political difficulties, the party can hardly look to him to lead them out of the morass. “If we had a coach,” said John Feehery, who was press secretary to Representative J. Dennis Hastert when Mr. Hastert was the House speaker, “the coach would take us in the locker room and scream at us.”

Some Republicans are indeed screaming, particularly the party’s social conservative wing, which places a high priority on ethics and family values. Tony Perkins, the president of the Family Research Council, a conservative advocacy group in Washington, said the elections of November 2006, in which Republicans lost control of the House and the Senate, proved that voters want politicians in Washington to clean up their act.

“Exit polls show that was the No. 1 factor in depressing Republican enthusiasm,” Mr. Perkins said in an interview Tuesday. “There is an expectation that leaders who espouse family values will live by those values. And while the values voters don’t demand perfection, I do believe they want leaders with integrity.”