For Fallon, the perception of a disagreement with Bush's policies on Iran rather than an actual rift was enough reason to step down.

"Recent press reports suggesting a disconnect between my views and the president's policy objectives have become a distraction at a critical time and hamper efforts in the Centcom region," Fallon said in a statement Tuesday in which he announced his resignation as head of U.S. Central Command, arguably the most important in the U.S. military.

Democrats seized on Fallon's resignation as an opportunity to criticize Bush.

"Over the last seven Bush years, we've seen those who toe the company line get rewarded and those who speak inconvenient truths get retired," Sen. John Kerry, D-Mass., said in a written statement.

Spitzer was the initial target of the investigation and was tracked using court-ordered wiretaps that appear to have recorded him arranging for a prostitute to meet him at a Washington hotel in mid-February, the official said.

The official spoke to The Associated Press condition of anonymity because of the sensitivity of the investigation.

The scandal surrounding the man who built his political reputation on rooting out corruption stunned the state. Calls for Spitzer's resignation began immediately and intensified Tuesday with the New York Daily News, New York Post and Newsday all demanding that he step down.

Spitzer retreated from public view Monday afternoon, when he appeared glassy-eyed with his shellshocked wife, Silda, at his side and apologized to his family and the public, but did not directly acknowledge any involvement with the prostitute.

Jim Clark, who was the former governor's chief of staff, agreed to plead guilty to a single count of conspiracy fraud in a filing in U.S. District Court in Anchorage. He was scheduled to enter his plea at an arraignment hearing on Tuesday.

Clark admitted to taking $68,550 in illegal contributions from the state's largest oil-services company, VECO Corp, for Murkowski's failed 2006 reelection bid in exchange for working on VECO's behalf to secure an industry-friendly version of tax legislation, according to the plea agreement.

He is the first official from the Murkowski administration to be charged in a federal criminal investigation that has so far resulted in convictions of three former state lawmakers, the indictment of a fourth and guilty pleas from two top VECO executives and one former lobbyist.

Murkowski, who was also a former U.S. senator, was soundly defeated in the 2006 Republican primary by Sarah Palin, Alaska's current governor who ran as an anti-corruption reformer.

Clark and VECO conspired to hide the illegal contributions "in a manner so that the public would be deceived and the payments would not be disclosed, as required by law," according to charging documents.

The federal investigation centers around a revision of an oil-tax law that passed the state legislature in 2006 at Murkowski's urging. Bill Allen and Rick Smith, two former VECO executives, pleaded guilty to bribing state lawmakers for a pro-industry version of the bill and other favorable actions.

Former state Senate President Ben Stevens, son of powerful U.S. Senator Ted Stevens, received much of that bribe money, Allen and Smith testified in court last year.

"I'm very disappointed in the article. It's not true," the likely Republican presidential nominee said as his wife, Cindy, stood beside him during a news conference called to address the matter.

"I've served this nation honorably for more than half a century," said McCain, a four-term Arizona senator and former Navy pilot. "At no time have I ever done anything that would betray the public trust."

"I intend to move on," he added.

McCain described the woman in question, lobbyist Vicki Iseman, as a friend.

The newspaper quoted anonymous aides as saying they had urged McCain and Iseman to stay away from each other prior to his failed presidential campaign in 2000. In its own follow-up story, The Washington Post quoted longtime aide John Weaver, who split with McCain last year, as saying he met with lobbyist Iseman and urged her to steer clear of McCain.

Weaver told the Times he arranged the meeting before the 2000 campaign after "a discussion among the campaign leadership" about Iseman.

But McCain said he was unaware of any such conversation, and denied that his aides ever tried to talk to him about his interactions with Iseman.

"I never discussed it with John Weaver. As far as I know, there was no necessity for it," McCain said. "I don't know anything about it," he added. "John Weaver is a friend of mine. He remains a friend of mine. But I certainly didn't know anything of that nature."

His wife also said she was disappointed with the newspaper.

"More importantly, my children and I not only trust my husband, but know that he would never do anything to not only disappoint our family, but disappoint the people of America. He's a man of great character," Cindy McCain said.

The couple smiled throughout the questioning at a Toledo hotel.

The published reports said McCain and Iseman each denied having a romantic relationship. Neither story asserted that there was a romantic relationship and offered no evidence that there was, reporting only that aides worried about the appearance of McCain having close ties to a lobbyist with business before the Senate Commerce Committee on which McCain served.

The justices' decision Tuesday includes no comment explaining why they turned down the appeal from the American Civil Liberties Union.

The ACLU wanted the court to allow a lawsuit by the group and individuals over the warrantless wiretapping program. An appeals court dismissed the suit because the plaintiffs cannot prove their communications have been monitored.

The government has refused to turn over information about the closely guarded program that could reveal who has been under surveillance.

That bill also would have shielded from lawsuits telecommunications companies that helped the government wiretap U.S. computer and phone lines after the Sept. 11 terrorist attacks without clearance from a secret court that was established specifically to oversee such activities. In its competing version of the legislation, the House intentionally left out that feature.

"American citizens must understand, clearly understand that there's still a threat on the homeland. There's still an enemy which would like to do us harm," Bush said. "We've got to give our professionals the tools they need, to be able to figure out what the enemy is up to so we can stop it."

"By blocking this piece of legislation, our country is more in danger of an attack," he said.

Democrats, in turn, accused Bush of fear-mongering and misrepresenting the facts.

"This is not about protecting Americans. The president just wants to protect American telephone companies," Rep. Rahm Emanuel of Illinois, head of the House Democratic Caucus, said Friday.

Beyond the rhetoric, the central issue is what the government can and can't do come midnight Saturday, when a temporary eavesdropping law adopted by Congress last August expires.

That law let the government initiate wiretaps for up to one year against a wide range of targets. It also explicitly compelled telecommunications companies to comply with the orders, and protected them from civil lawsuits that may be filed against them for doing so.