(CNN) - John McCain waded into the controversy over Barack Obama's ties to Weather Underground founder William Ayers Sunday, telling an interviewer that the Illinois senator’s relationship with the activist was "open to question," and his explanation of their connection “borders on the outrageous.”
The presumptive Republican nominee raised the issue himself during an interview on ABC’s This Week, in response to a question from host George Stephanopoulos about whether he believes Obama is as patriotic as he is.
“I'm sure he's very patriotic. But his relationship with Mr. Ayers is open to question,” said McCain.
“He became friends with him and spent time with him while the guy was unrepentant over his activities as a member of a terrorist organization, the Weathermen,” said the Arizona senator.
“Does he condemn them? Would he condemn someone who that says they're unrepentant and wished that they had bombed more?”
The Obama campaign responded a short time later. “Unable to sell his out-of-touch ideas on the economy and Iraq, John McCain has stooped to the same smear politics and low road that he denounced in 2000," said Obama campaign spokesman Bill Burton. "The American people can’t afford a third term of President Bush’s failed policies and divisive tactics.”
Hillary Clinton said during Wednesday’s presidential debate that Obama’s meetings with Ayers were one element of a “larger set of concerns” about how Democrats would be able to beat McCain this fall.
Obama has said that he an Ayers were only passing acquaintances, a characterization disputed by the Clinton campaign.
McCain took issue with Obama’s reply to questions about the 60s-era activist at the Philadelphia debate: that he was “also friendly” with GOP Sen. Tom Coburn, “who during his campaign once said that it might be appropriate to apply the death penalty to those who carried out abortions.
“Do I need to apologize for Mr. Coburn's statements?” said Obama. “Because I certainly don't agree with those either.”
On Sunday, McCain said Coburn was “a great humanitarian… in my view, one of greatest spokespersons for the rights of the unborn.”
“To compare [Ayers] with Dr. Coburn, who spends so much of his life bringing babies into this world, that in my view… borders on outrageous,” McCain said.