Click here to watch "Celeb."

The debate over John McCain's "Celeb" ad, which intersperses images of Barack Obama with shots of Britney Spears and Paris Hilton, rages on. In today's edition of "National Journal On Air," host Tammy Haddad broached the controversy with no fewer than eight guests.

Obama spokesman Bill Burton said the ad's content, as well as McCain's defense of it, was "ridiculous." Hotline's Jennifer Skalka characterized it as a "demeaning, derogatory ad." The Huffington Post's Hilary Rosen found it ironic that McCain, who she said had capitalized on his own celebrity status, was now "whining about someone else's fame."

Atlantic Media political director Ronald Brownstein took the critique a step further, arguing that "by associating Obama visually" with "two young white women," the McCain camp was playing the "race card" in a manner reminiscent of the controversial 2006 Republican National Committee ad (subscription) run against Tennessee Senate candidate Harold Ford Jr. XM radio host Joe Madison echoed this assessment, bristling at the ad's comparison between Obama and "two blonde bimbos."

Atlantic senior editor Ross Douthat took issue with this racial reading, but did acknowledge that he found the ad "frivolous and stupid." Republican consultant Alex Castellanos, who himself once produced a controversial, racially charged spot -- Jesse Helms' 1990 "Hands " -- said "Celeb" raised a legitimate point: "Fame without substance can be a trap." But he questioned whether its less-than-serious tone reflected well on the McCain camp.

The only unapologetic defense of "Celeb" came from McCain economic adviser Nancy Pfotenhauer, who insisted that its real subject was energy costs. "All it does is give a nod at the beginning to the fact that Senator Obama is a world celebrity," she said.

The interviews with Burton, Pfotenhauer and Madison, as well as the panel discussion with Rosen and Castellanos, can be heard here. The roundtable discussion featuring Brownstein, Douthat and Skalka can be heard here.