Â鶹ӰÊÓ

Already advertising at record levels, Barack Obama has scheduled a half-hour commercial for prime time on Oct. 29, six days before Election Day.

Obama campaign officials said the campaign had secured a 30-minute block of time at 8 p.m. on CBS and NBC. CBS was already juggling its prime-time lineup to accommodate the Democratic presidential candidate, moving back an episode of "The New Adventures of Old Christine."

Such a vast purchase of commercial time is a multimillion-dollar expense, but Obama has been spending dramatically on ads, overshadowing rival John McCain and the Republican National Committee.

Short political spots have been the traditional way for politicians to communicate with voters. But a prime-time, sitcom length commercial would provide Obama an opportunity to make a closing argument to the entire country.

"It's a luxury to be able to afford that kind of communication," said Tad Devine, a Democratic media consultant who was a senior adviser to John Kerry's 2004 presidential campaign.

That Obama has the ability to buy such a huge block of prime time is a testament to his prodigous fundraising. He has not been shy about spending it.

On Monday, for instance, he spent $3.3 million in TV advertising on Monday. At that rate he will spend more than $90 million on ads through Election Day -- more than all the money Republican rival John McCain has to spend on his entire fall campaign.

McCain's ad spending Monday totaled about $900,000 and the Republican National Committee weighed in with about $700,000 worth.

All whopping numbers, but the disparity between Obama and the Republicans is so wide that it has allowed Obama to spend in more states than McCain, to appear more frequently in key markets and to diversify his message by both attacking McCain and promoting his own personal story.

With national and state polls showing him building a broader lead over McCain, Obama has switched to a more positive pitch. Last week, only 34 percent of his ads attacked McCain directly while virtually all of McCain's ads attacked Obama, according to a study by the Wisconsin Advertising Project at the University of Wisconsin-Madison.

One of Obama's most recent ads came as Sarah Palin, McCain's running mate, made an issue of Obama's connections to 1960s radical Bill Ayers and argued that Obama "is not a man who sees America like you and I see America."

The ad bespeaks Americana. In it, Obama recalls being a child, sitting on his grandfather's shoulders and waving an American flag as they watched astronauts return from a splashdown. "And my grandfather would say, 'Boy, Americans, we can do anything when we put our minds to it.'"

The ad offers a direct response to Palin. But it also illustrates Obama's continuing need as an African-American to reassure voters about his candidacy.

Outside groups weigh in

Boosted by an economy in crisis and a saturation of advertising, Obama has built up his margins over McCain in Democratic-leaning battlegrounds such as Pennsylvania and Michigan. He has tilted Republican-leaning states such as Colorado and New Mexico toward his side. And he has created contests in such reliably Republican states as Indiana, Virginia and North Carolina.

At the same time, outside groups have weighed in on both sides. VoteVets.org, a group critical of Bush war policies, on Wednesday began spending $350,000 on ads in Virginia criticizing McCain for opposing full college scholarships for those who serve three years in the military.

Health Care for America Now, a coalition that includes unions and patient advocates, is airing an ad in Ohio and on national cable criticizing McCain's health care plan, echoing a similar message in an Obama ad.

By now, McCain's allies had hoped the Arizona senator would have established his dominance in states won by President Bush in 2000 and 2004 and would have focused on winning two of the three key Rust Belt states of Pennsylvania, Ohio and Michigan.

But McCain stopped advertising in Michigan, Obama leads in Pennsylvania and he has the edge in Ohio.

"Money doesn't always mean victory, but it means that you have more options to cover more of the battlefield," Republican strategist Terry Holt said. "We're going to have to win with less."

Less is right. Obama is outspending McCain in practically every one of the 14 states the two camps are contesting. One exception is Iowa, where McCain spent more than Obama even though Obama has been sitting on a comfortable lead in the polls.

The biggest discrepancy exists in North Carolina, where Obama spent eight times more than McCain on ads, according to the Wisconsin Advertising Project and TNS Media Intelligence/CMAG, which tracks political ads.

Obama's spending advantage in North Carolina might reflect the McCain campaign's reluctance to devote resources to a state that might ultimately follow precedent and vote Republican anyway. But polls in the state show Obama closing the gap.

Meanwhile, Obama's ability to spend is restrained only by his ability to raise money.

He is the first major party candidate to decline public financing in the general election, leaving him free to spend as much as he can raise. McCain, on the other hand, is limited to spending only the $84 million in public funds he accepted to cover all his costs in September and October.

The RNC is helping with its own resources. It raised a record $66 million in September. Obama has not disclosed his September finances; he doesn't have to until Oct. 20, when financial reports are due to the Federal Election Commission.

Even with their combined resources, McCain and the RNC trailed Obama in ad spending last week by more than $6 million.

"That is a message imbalance that you just can't overcome," said Evan Tracey, head of TNS/CMAG. "That's like one side of the stadium yelling, 'Tastes Great!' and the other side, you can't hear them."