McCain ready for debate battle

WASHINGTON -- As they prepared Monday for their presidential debate tonight, John McCain attacked Barack Obama's credibility. Some of McCain's fellow Republicans say the aggressive tack may not offset the damage to his candidacy from the sinking economy.

On a day when the stock market dipped below 10,000 points for the first time in years, McCain served notice at an Albuquerque rally that he'll be combative in the debate. As he discussed mortgage giants Fannie Mae and Freddie Mac, McCain said Obama has accused him of opposing regulation that would have averted the financial crisis.

"I guess he believes if a lie is big enough and repeated often enough, it will be believed," McCain said.

Obama, taking time out from debate practice in Asheville, N.C., said the candidates should talk about the economy rather than "the usual political shenanigans and smear tactics."

"The American people are losing right now," the Democrat said. The back-and-forth came as polls show McCain losing ground. Obama is leading McCain or essentially tied with him in key states won by President Bush in 2004, including Ohio, Florida, Virginia, Nevada and North Carolina, according to surveys compiled on RealClearPolitics.com.

GOP pollster Steve Lombardo said the window for McCain to challenge Obama's character may be closed. GOP strategist Mark Corallo said the McCain campaign's line of attack on Obama is "about a week too late."

"The economic situation has virtually ended John McCain's presidential aspirations, and no amount of tactical maneuvering in the final 29 days is likely to change that equation," Lombardo wrote to his clients.

Another GOP pollster, Whit Ayres, said the Wall Street crisis "makes Sen. McCain's task more challenging" but noted that it's early to count him out.

McCain's running mate, Sarah Palin, again sought to link Obama to 1960s radical William Ayers, a founder of the Weather Underground group accused of several bombings. Ayers once hosted a 1995 reception for Obama and served with him on two boards.