>What do you mean "personally" ? Are you expecting a process to behead the Prime Minister or something ?

I don't know precisely what they were thinking, but in America someone who is impeached and convicted by the Senate can be personally barred (by simple majority vote at that point) from ever holding any federal office ever again, which seems the political equivalent of a "beheading".

I presume Congress, like Parliament, cannot bind its future self, so "barring" a leader is just a pinky swear because any future Congress can just "unbar" them. The thing about beheading is that you can't undo it, cos that's not Man's law keeping them dead.

Charles I was beheaded. Even if the day after Parliament had thought better of it, their only option was to make somebody else King instead, Charles I was dead.