How come Charlie Sheen and Newt Gingrich don't get the same punsihment?

Bill Maher as usual does incredibly funny and intelligent commentary with no punches pulled. The Sheen-Gingrich comparison is great, but the Gingrich-Edwards one is a really interesting one to ponder. And from there it slaloms through Ensign and Vitter and Spitzer and on and on. It is a strange old world that some people live in.