What would the penalty be for punching a government official in the face?

Say someone were to meet a government official, (as in a Representative, someone from the Senate, or someone in the President’s cabinet.. *In America by the way) and punch them in the face. For the sake of argument, let’s say they deserved it. They were punched just once, and it was a first time offense. What would be the penalty. Assault charges? I know that assaulting a police officer carries a weightier penalty. Would the sentence be larger given that that person is important?