The church has no business being or becoming a political entity. That is NOT the mission of the church or Christ.
Like, the Church should not teach anything on say, abortion?
It is part of the mission of the Church to transform the world.
The Church serves as an important instrument to focus and amplify the voices of its individual members and has every bit as much right to do so as any labor union, PAC, corporation or non-profit.
A nation's political life, like Christianity itself, is meant for everyone, and everyone has a duty to contribute to it, even Catholics.
Democratic pluralism does not mean that Catholics, individually or collectively, should be quiet in public about serious moral issues because of some misguided sense of good manners. A healthy democracy requires vigorous moral debate to survive. Real pluralism demands that people of strong beliefs will advance their convictions in the public square -- peacefully, legally and respectfully, but energetically and without embarrassment. Anything less is bad citizenship and a form of theft from the public conversation.