Well, if everyone in the country were Catholic, then it could be that there would be a different consensus about what is right and what is wrong.  That is, after all, what many of our laws are based on.  Eg, as a society, we agree that stealing is wrong and harmful to the social order, so we outlaw it.  There was a time when domestic violence and marital rape were not seen by society in general as being sufficiently wrong to be against the law.  That has changed.  If the population of this country were all Catholic, their views might be more in conformance with the teachings of the church, and laws might be changed to reflect the views of that type of society.