As the FBI opened criminal charges, the Republican party was scrambling yesterday to try to prevent a scandal involving a former congressman's illicit e-mails to underage pages from enveloping the party's entire House leadership and dealing a further blow to its hopes at November's mid-term elections.
Hours after Dennis Hastert, the House speaker, called for a full investigation of the affair, Mark Foley, the former Florida congressman accused of exchanging sexually explicit messages with the 16- and 17-year-old pages, announced that he had entered a rehabilitation centre to be treated for alcoholism and for what he called "other behavioural problems".
Mr Foley abruptly resigned his seat on Friday, as details of the scandal became known. No less damaging, however, it emerged that members of the Republican House leadership knew of Mr Foley's contacts with the pages late in 2005 - two years after he first began sending the messages.
Mr Hastert himself first claimed that he found out about the matter last week. But another Congressman claimed he had told the Speaker "months ago" about what was happening. Democrats have seized on the scandal, insisting Mr Hastert and his colleagues had staged a deliberate cover-up to protect Mr Foley's seat in the November elections, whose outcome is on a knife-edge.
The allegations were "repugnant" said Harry Reid, the Democratic minority leader in the Senate. "But equally as bad is the possibility that Republican leaders in the House of Representatives knew there was a problem and ignored it to preserve a Congressional seat."
The Foley affair was the second major embarrassment to hit the party at the weekend, after the new book by the Washington Post reporter Bob Woodward, which paints a picture of Bush administration incompetence and deceit in handling the Iraq war, and also charges that it ignored urgent CIA warnings before 9/11 that a terrorist attack was likely.
Though very different in nature, the two episodes strike at the two issues which Republicans were banking on to preserve their slender majorities in the House and Senate this autumn: their superior competence on national security, and their claim to better represent American values than their Democratic opponents.
Over the weekend, the White House was offering a point by point rebuttal of the most damaging charges in the Woodward book, including its claim that Andrew Card, the former chief-of-staff, had twice sought in vain to persuade President George Bush to dismiss his Defence Secretary Donald Rumsfeld.
It also hotly denied that Condoleezza Rice, President Bush's national security adviser at the time, had in July 2001 paid scant attention to a personal warning from George Tenet, then the CIA director, that the warning light was "flashing red" about an al-Qa'ida attack.
Mr Foley's problems do not involve the White House. But, as Ed Rollins, an influential former Republican political consultant, says: "It goes to the credibility of the leadership. This is going to turn off religious right voters and other conservatives", and will make it more difficult to get Republicans to the polls.