What you're saying is nonsense. The Senate can't issue any punishment except removal from office and prohibition on future federal office.

They also wouldn't sentence him to death even if they could. You think these treasonous fucks want there to be a precedent that extra-judicial killing of political opponents accused of "inciting insurrection" is fine and dandy? Congress wouldn't be able to leave their offices without getting clipped by either a fellow politician or a constituent.