"I do this think this is a total reaction to that article," he said. "This article appeared on [Friday] and boom, we get a phone call on the weekend for this appearance," he said.

Kenneth Lisaius, a spokesperson for Bush, said there was nothing special about the McCain invite.

"I would say [that] the invitation was extended like it was to other Republican office-holders," he said.

He said the campaign welcomes McCain's "strong support."

As to whether McCain will serve as a proxy to the press following the debate, Lisaius said, "It'll be hard for [him] to leave the hall without talking to a reporter."

Serving as a surrogate, however, is not how McCain staffers conceive the invitation.

And as to limiting the number of joint appearances, Davis said he has another concern: that McCain maintain his image as a statesman.

"It's important when you're--as the Wall Street Journal indicated today--the most popular public figure in America that you handle that in a responsible fashion," Davis said.