Education professor Bill Ayers must be breathing a sigh of relief. The University of Illinois academic, who has written extensively on inner city schools, could have faced further abuse had Barack Obama lost the US presidential election.

His links to Mr Obama, though tenuous, were used by the Republicans in one of their most damaging attacks on the Democrat campaign.

Professor Ayers (above) was a founder of Weather Underground, a hard-left movement responsible for a series of bombings of US public buildings in the 1960s and 1970s. By the 1990s, he was a respected educationist and author.

He served on the board of two Chicago organisations with Senator Obama, one an education-based project, the other an anti-poverty foundation, and his wife held a gathering at which the previous Illinois senator introduced Mr Obama as her successor.

This led vice-presidential candidate Sarah Palin to accuse Mr Obama of “palling around with terrorists” and for Republican supporters to run advertisements asking: “Why would Barack Obama be friends with someone who bombed the Capitol and is proud of it?”

For Professor Ayers, the publicity has resulted in hundreds of abusive messages to his blog. One person threatens to wring his neck and urinate on his grave. In response, he has posted a list of his books on education and adds: “Make up your own mind and send me a comment.” Few of his critics have taken up his challenge, but it has spurred many teachers to write about his positive influence on their work.