What Role Should Churches Play In Campaigns?

Over at Street Prophets, Chuck Currie asks an interesting question: What Role Should Churches Play in Campaigns?

The United Methodist Social Principles correctly state that "churches should not seek to use the authority of government to make the whole community conform to their particular moral codes. Rather, churches should seek to enlarge and clarify the ethical grounds of public discourse and to identify and define the foreseeable consequences of available choices of public policy." Churches have both a legal right and a theologically-centered obligation to be involved with the life of the world and while our churches should not be engaged in partisan efforts we should be involved in public policy debates.

I think many people would agree with what Chuck says here. Yet...

What is disturbing to me about this view of the church is the assumption that the one's religious beliefs are a private matter that do not belong in the realm of public debate and discussion. Of course the inconsistancy here that that it is only certain "religious beliefs" that should be a private matter. The "religious belief" of secular humanism is of course given a place at the table of public discourse.

Thoughts?