If the guy said the words "George Bush" and "death" in the same sentence, he faces jail time.
Rightly so. He'd be threatening the institution of the Presidency, the U.S. Constitution, and the lives of every American by default in uttering those words.
And if he's on the public airwaves when he said them, he's in even bigger trouble.
Depending on the exact language, there is a possible charge of sedition.
Also after the JFK assassination, it became a Federal crime to plan/plot/attempt to kill the President (and I believe this holds for ex-Presidents and even candidates once they reach a certain stage, note the Secret Service for people who have not been elected President).