"Again, a double standard. When the head of a major union in the United States of America says that you've got to 'take out,' then that's OK. But when Mitt Romney in a middle of a town-hall meeting doesn't immediately repudiate a remark — and of course Mitt Romney doesn't think the president should be tried for treason — but people are free to give their opinion at town-hall meetings. That's what town-hall meetings are all about," McCain said on the "Kilmeade & Friends" radio program.

The former Republican presidential candidate said that complaints from the Obama camp sought to distract from more substantive campaign issues.

"The fact that Mitt Romney didn't immediately repudiate what this woman said, fine," McCain said. "Nobody believes Mitt Romney thinks the president should be tried for treason. This is just the kind of thing that is going to go on and on and on which distracts from the president's national security failures and, of course, an economy that is still limping along."

Romney addressed the controversy with reporters after the town hall, clarifying he did not believe the president should be tried for treason.

"No, of course not," Romney said.