"It's got to stop," he said of the excesses, which also led to corruption among members of Congress. "We're going to have to clean up our act."
On the Iraq war, McCain said the "titanic" struggle pits supporters of the nation's values against those of radical fundamentalism.
"We lose this war and come home, they'll follow us home," he said.
McCain has strongly backed President Bush's troop "surge" in Iraq, but he has conceded that his presidential aspirations would be seriously hurt if US casualties are not down by next year.
Voter concerns about his Iraq stance were also apparent as McCain made a brief campaign foray into New York last week. He was asked about it by some of the several hundred donors who paid $1,000 or more to attend a fund-raiser Thursday night.
In South Carolina yesterday, McCain was told that some Republicans think he is not conservative enough.
"I think you should judge people by their record," said McCain, who trails former New York mayor Rudolph Giuliani in polls. "I am conservative across the board and I will match my record with anybody in America, much less anybody who is running."
Although he has been ahead in the polls, Giuliani continues to face some questions among conservatives over his troubled family relationships.
Twenty-seven years after Ronald Reagan became the only divorced candidate to win the presidency, Giuliani is hoping that when it comes to family values, voters will be as accommodating.
Republican strategists say Giuliani's family issues are likely to hinder his standing among conservatives who already have questions about his positions on social issues. They say the estrangement could raise a question in voters' minds: If Giuliani can't keep his family together, how will he keep the country together?
Giuliani's support for abortion and gay rights, his backing of gun control measures, and his very New Yorkness have already given conservatives pause about his candidacy. He has also marched in gay pride parades, dressed up in drag, and lived temporarily with a gay couple and their Shih Tzu.
Then came the stories about his family.
