Thank the Lord that it entirely possible to govern this country as a Constitutionalist, while at the same time trying to live one's life based on the teachings, vaules and opinions of the Catholic Church. Otherwise, a President Gingrich should be expected to award clemency to virutally every capital appeal that came across his desk, and to avoid military interventions like the one we engaged in in Afghanistan. Can't have it both ways.
Try reading the Catechism of the Catholic Church sometime, in order to correct your misconceptions regarding what the Church actually teaches.