Obama says something Mr. Carter seems to have trouble remembering: "We have one president at a time.”

From The New York Times:

“I’m more interested in listening than doing a lot of talking,” Mr. Obama told reporters before leaving Washington for a trip cloaked in secrecy because of security concerns. “And I think it is very important to recognize that I’m going over there as a U.S. senator. We have one president at a time.”