Dr. Bill Ayers, who taught as a visiting professor at Vassar for the 2005-2006 academic year, has been the focus of anti-Obama groups for some time now. Ayers was a member of the radical activist group Weather Underground in the 1960's and is currently a professor at the University of Illinois-Chicago.
A new ad sponsored by the right-wing American Issues Project, attacks Obama for his connections to Ayers.
A sample of the narration from the ad:
"How much do you know about Barack Obama? [...] The Capitol was bombed thirty years before - By an American terrorism group called Weather Underground that declared 'war' on the U.S. - Targeting the Capitol, the Pentagon, police stations, and more. One of the groups leaders, William Ayers, admits to the bombings, proudly stating: 'We didn't do enough' [...] 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."
Update: Ayers taught Urban Education Reform during his time at Vassar.