John McCain had an adulterous affair. How can family values voters rationalize that?

The President's main responsibility is NOT to regulate family values. Ultimately, the individual has the most power over this issue. On the other hand, foreign policy, the war, immigration....these are issues that the President has more power over. So...most Republicans would rather vote for someone who will do right in the areas that are in the President's realm of responsibility - and take care of personal values on their own...