Assuming that the behaviour is not illegal, I'd penalize more for professional misconduct than personal. I don't care what someone does in their private life, on their own time. If the personal misconduct is committed on the job, then it is most likely professional misconduct also and is therefore a double whammy.
I don't believe what a person does in his/her private life speaks to their professional competence. I hire people for the work they do on the job and as long what they do after hours doesn't compromise their work (i.e: drinking/drugs, etc) I have no issue with it.
Integrity??? I thought you said we were talking about politicians?