Most Americans say that “private” moral character doesn’t affect fitness for public office.  Yet though many will vote for an adulterer, far fewer will vote for a wife-beater.

What this shows is that they do think moral character affects fitness for public office.  They merely don’t consider marriage vows important enough.

The problem lies not in the fact that they distinguish among vices, for some really are worse than others.  It lies in where they draw the lines, for it is hard to believe that a candidate will keep faith with his constituents if he cannot keep faith with his wife.

“He who is void of virtuous attachments in private life is, or very soon will be, void of all regard of his country.  There is seldom an instance of a man guilty of betraying his country who had not before lost the feeling of moral obligations in his private connections.”  --  Samuel Adams to James Warren, 4 November 1775.