I am only interested in the Catholic position. Prior to V2, the official position of the Church was "error has no rights." But given our  current position supporting the absolute primacy of conscience and freedom of conscience, it is wrong for us to push for laws that violate the conscience of others. 

Abortion is a particularly horrible example of this principle for the following reason. Our believe that abortion is immoral ultimately depends on our conviction of life beyond the grave, which forces us to ask when that immortality begins, we have concluded it begins in the earliest stages of pregnancy...so abortion is taking of human life.

But our believe in freedom of conscience forces us to take the perspective of the other, and we are forced to concede that for those who do not accept immorality, for those who believe that this life is all there is, the fetus reasonably (albeit incorrectly) be understood to be non yet fully human life. 

Your other instance are different.