In 1973, Ibershof tried to put William Ayers, a founding member of the Weather Underground, in prison for an alleged conspiracy to bomb political targets. Ayers, now an education professor in Chicago, has become a fixture in John McCain’s attempt to raise doubts about Barack Obama.

“I had a sizable room full of files with wiretaps that were not obtained by court order,” he said.

The illegal tactics were ordered by Atty. Gen. John N. Mitchell and FBI assistant director W. Mark Felt, who was later unmasked as the Watergate scandal’s “Deep Throat,” Ibershof said. They were part of a plan, exposed during the Watergate hearings, to use “espionage techniques” to gather intelligence on domestic foes.

Obama met Ayers when the former radical hosted an event to introduce Obama at the start of his political career. The two have served together on boards, but are not close.

“It seemed manifestly unfair to tar him with this association,” Ibershof said in a telephone interview this weekend from his home in Mill Valley. “Sen. Obama had known Ayers during a period he was named Citizen of the Year in Chicago, not when he was committing those terrorist acts.”

McCain supporters have denounced Ayers as an “unrepentant terrorist.” Ibershof said he believes people deserve a chance to redeem themselves, “a human reaction anyone would have.”

“Mr. Obama, was, as he has noted, just a child.”