Sen. John McCain was put on the defensive Sunday for comparing some of his GOP colleagues to hobbits during the debt ceiling debate.

The Arizona Republican had taken to the Senate floor in July to admonish conservatives for “unrealistic” expectations and quoted a Wall Street Journal editorial that compared them to the characters from J.R.R. Tolkien’s “The Lord of the Rings.”

“What I was talking about, quoting from a Wall Street Journal editorial, was that there was a segment of the Republicans in the Senate — Republican Senators — that said we cannot raise the debt limit until we pass a balanced budget amendment to the Constitution,” McCain said when asked on CBS’ “Face the Nation” about his choice of words. “The Senate would not pass — would not get 67 votes. … We could not have passed it. That was unrealistic, hobbits are unrealistic, it was unrealistic to say.”

McCain, who ran against Barack Obama in the 2008 presidential race, said he had not heard whether his former running mate, former Alaska Gov. Sarah Palin, will join the 2012 GOP presidential field. Karl Rove, a former senior adviser for President George W. Bush, predicted on “Fox News Sunday” that Palin would enter.

“She has not asked my advice, and I do not know” whether Palin will run, McCain said. “I certainly put some credence to Karl Rove.”

McCain plans to “take a while” before supporting a GOP candidate, he said.

“My sympathy is with all of you,” McCain said of the contenders. “I’m glad I’m not with you.”