Besides, if you are running for president or VP, you should resign your elected post. Obama, Liberman and John Friggin Kerryshould have, You are not representing your constituents as you should if you are out on the campaign trail.
He did it in the office. If he did it upstairs in the private quarters in the evening, that's different.
Go and screw one of your employees in your office and have the boss find out- see how long you last.
Democrats can murder someone (Ted Kennedy), rape someone (Slick Willie - Juanita Broderick (remember"Put some ice on it?)
or be an officer in a racist organization (Robert KKK Byrd ) and nothing happens.