What that implies to me is that the church will use those numbers to say, "Look, we support this and we have X million followers! It's popular!"--trying to emphasize how many people they have who allegedly support the legislation. Not that they have greater representation in the legal system because of it, but that they can put more pressure on the representatives who are there. If people leave, that decreases the leverage the church has because X-minus-1 million is not as impressive as X million.
*nods* I agree with this.