We're all liars, a bit. We can have the dorm room debate over whether it's our basic desire to be good that keeps us from going Full Trump all the time, or just the fear of the consequences, but I'll submit it's a bit of both.
Senators who have been in office for decades, surrounded by a staff of lickspittles and a mostly obsequious press that can't figure out whether to hand out medals when someone asks as Hard Kweschin or drum them out of the profession for being rude, do lack a bit of an external check on their behavior that most of the rest of us have.
