Sorry, Newt.

Sen. Marco Rubio won't be endorsing you in the primary, despite fresh speculation triggered by Gingrich's hiring of a former top Rubio campaign staffer.

"No, man. I already told you guys I'm not endorsing anybody," Rubio jabbed lightheartedly this morning after appearing at the Foreign Policy Initiative Forum. "Why do you guys ask me that? I haven't changed my mind, sorry."

Gingrich endorsed Rubio in his Senate race last year and has said he'd want Rubio as his running mate. But so does Mitt Romney, whom Rubio has ties to as well. The smart strategy, as it was from the start of his up and down primary, is to stay on the sidelines until a nominee is picked.

Below, video from the FPI forum.