What do these men have in common?

Newt Gingrich
Bob Livingston
Larry Craig
Mark Foley
Bill Clinton
Don Sherwood
John Edwards
Barney Frank
Eliot Spitzer
John Ensign
Mark Sanford
(and that's just the ones who come to mind easily)

As a society, we can continue to purge politicians for private behavior rather than the quality of their public service - or not. Who wins when we do this? Who loses?