We have little say in our government, which is different from Christianity or corporations, in which one has no say, but after choosing who will rule the country, it's largely out of our hands. And I do believe that religion can have a detrimental effect on the masses, should they decide that their lives can be bettered through prayer instead of social change. I think the secondary purpose of religion is to make explicit certain cultural rules. When these rules become integral to the society, they are often made into law. The best example is marriage.
Some religions permit various styles of polygamy, yet American laws prohibit such things.
Well, find a new country, I guess. For better or for worse, they don't allow it here. Now we get to a tricky part, specific to the United States. The state overrides your free religious expression, and most would agree that that is a good thing. It's an issue of the rights of the few and the rights of the many.