Republican John McCain jettisoned much of his campaign's angry tone on Monday as he declared that his race for the presidency was not over and that he had the experience and fighting spirit to lead the nation out of crisis.

In a departure from the sharp personal attacks against Barack Obama in recent weeks, McCain adopted the more positive message he used during the primaries. Although he painted a pessimistic picture of the U.S. economy -- indeed, of the entire American way of life -- he said the calamitous situation could be made right by the forceful leadership he was prepared to provide.

"I've been fighting for this country since I was 17 years old, and I have the scars to prove it," he said at a rally of more than 10,000 people in Virginia Beach and then again at a smaller gathering at Cape Fear Community College in Wilmington, N.C. "If you elect me president, I will fight to take America in a new direction from my first day in office until my last."

In recent days, McCain has faced withering criticism from Republicans for running what they call an intensely negative campaign that offers no rationale for his candidacy and may well damage the party for years to come. The speech appeared to be intended as an antidote, and aides suggested that McCain would stick with this new message through the final three weeks of the campaign. He is also likely to adopt the tone in the critical final debate with Obama on Wednesday night.

Still, aides held out the possibility that McCain would change tactics yet again if warranted by events. Even on Monday, in an interview with CNN, McCain continued to criticize Obama for his association with the 1960s radical William Ayers, whom he called "an unrepentant terrorist." McCain said Ayers and his wife, Bernadine Dorhn, both founders of the Weather Underground, "want to still destroy America."

BIDEN SAYS MCCAIN AIMS TO DISTRACT

Democratic vice presidential nominee Joe Biden said McCain is falsely attacking Obama to distract voters from the economy while lurching from one bad idea to another.

"Every single false charge, every single baseless accusation is a simple attempt to get you to focus on something other than what's affecting your families and your country," Biden told about 500 people at an American Legion hall in Rochester, N.H.

"I've known John McCain for a long, long time," Biden said. "It's disappointing that his campaign, as a recent analysis has shown, literally 100 percent of the McCain campaign's advertisements are negative."

A study of all presidential ads in the largest 186 TV markets by the University of Wisconsin's advertising project found that nearly every McCain ad from Sept. 28 to Oct. 4 was negative, compared with 34 percent of Obama's.

OBAMA BUYS HALF-HOUR

ON TWO BIG NETWORKS

In a sign of his flush finances, Obama plans a half-hour prime-time broadcast on CBS and NBC on Oct. 29, the first time in years that a candidate has made such a substantial investment in national TV. Ross Perot, a billionaire who bankrolled much of his own campaign, drew an audience of 26 million to a 1992 simulcast on ABC and CBS. McCain accepted $84.1 million in public financing, and that is all he can spend. Obama rejected the taxpayer money, betting he could raise a lot more. And he has.