Obama buys 30-minute prime -time TV spots on CBS and NBC six days before the vote

Obama plans prime-time TV ad before Nov. 4He buys the 30-minute spots on CBS and NBC six days before the vote

WASHINGTON - 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 already was juggling its 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.

Ads have more positive pitch
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 comes as McCain makes an issue of Obama's connections to 1960s radical Bill Ayers and as McCain's running mate, Sarah Plain, argues 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.