Obama accuses McCain of 'losing his bearings'

The Illinois senator added: "For him to toss out comments like that, I think, is an example of him losing his bearings as he pursues this nomination. We don't need name-calling in this debate."

Like McCain, Obama criticized former President Carter for recently meeting with Hamas leaders, saying the U.S. must not negotiate with a terrorist group that is intent on Israel's destruction. McCain had called on Obama to repudiate Carter's meeting.

McCain's campaign issued an angry response that accused Obama of trying to divert attention from a legitimate question by raising McCain's age.

"He used the words 'losing his bearings' intentionally, a not-particularly-clever way of raising John McCain's age as an issue," McCain adviser Mark Salter said. "It is more than fair to raise this quote about Senator Obama, because it speaks to the policy implications of his judgment."

Obama spokesman Bill Burton insisted that Obama was not trying to do what McCain's campaign accused him of.

"Clearly, losing one's bearings has no relation to age," he said.

Thus far, Democrats have been careful not to mention McCain's age, at least not directly. The lone exception is Rep. John Murtha, D-Pa., a supporter of Hillary Rodham Clinton who a few weeks ago said the rigors of running the country is too much for guys their age.

"Let me tell you something, it's no old man's job," Murtha, 75, told a union audience.

In response, McCain told CNN: "All I can tell you is that I admire and respect Jack Murtha. Speak for yourself, Jack. I'm doing fine. Thanks."