You can watch the ad on the group's Web site.
"Beyond the speeches, how much do you know about Barack Obama?" an announcer asks as the spot opens. "What does he really believe? Consider this: United 93 never hit the Capitol on 9/11. But the Capitol was bombed thirty years before, by an American terrorist group called Weather Underground that declared 'war' on the U.S., targeting the Capitol, the Pentagon, police stations and more."
The announcer continues: "One of the group's leaders, William Ayers, admits to the bombings, proudly saying later: 'We didn't do enough.' Some members of the group Ayers founded even went on to kill police. But Barack Obama is friends with Ayers, defending him as, quote, 'Respectable' and 'Mainstream.' Obama's political career was launched in Ayers' home. And the two served together on a left-wing board. Why would Barack Obama be friends with someone who bombed the Capitol and is proud of it? Do you know enough to elect Barack Obama?"
The Obama campaign issued a response to the ad from spokesman Tommy Vietor saying that a key player in The American Issues Project, Ed Failor Jr., is a paid McCain consultant. (UPDATE: American Issues Project spokesman Christian Pinkston responds that Failor worked for the McCain campaign up until July of 2007 but now has no connection.)
"The fact that John McCain dispatched his paid consultant to launch this despicable ad from a so-called 'independent' committee shows how desperate he is to change the subject from his shocking disconnect with the economic struggles of the American people," said Vietor. "He knows that Barack Obama has denounced the detestable crimes that Bill Ayers committed forty years ago."
The Obama release points to an article from National Journal last year noting that Failor "signed on with 2008 White House hopeful John McCain this January," and links to an old McCain press release trumpeting the hire.
UPDATE: Both CNN and FOX News are declining to run the ad, the New York Times reports -- the former because of "a ban on negative advertisements from outside groups during the party conventions" and the latter "amid questions about its legality." (The Obama campaign pushed to reporters a Huffington Post story suggesting the spot may violate election law.) Pingston told the Times "he was confident the advertisement would have healthy exposure" in Michigan and Ohio.
Meanwhile, the McCain campaign is prepping an ad linking Obama to his old fundraiser Tony Rezko. (The RNC has been pushing this link hard today in response to the Obama campaign's offensive against McCain.)
As CBS News chief political consultant Marc Ambinder reports, a campaign official suggested that Obama "opened the door" to the ad.
The Obama campaign "attack Cindy," the aide said, in its ad today on John McCain not knowing how many houses he owns. "She owns the homes. I thought he said the wives were off-limits."
As Ambinder notes, the McCain camp "is widely perceived to [have] drawn first blood by attacking Obama's character."