Ronald Reagan said this quote

Let me speak plainly: The United States of America is and must remain a nation of openness to people of all beliefs. Our very unity has been strengthened by this pluralism. That's how we began; this is how we must always be. The ideals of our country leave no room whatsoever for intolerance, anti-Semitism, or bigotry of any kind -- none. The unique thing about America is a wall in our Constitution separating church and state. It guarantees there will never be a state religion in this land, but at the same time it makes sure that every single American is free to choose and practice his or her religious beliefs or to choose no religion at all. Their rights shall not be questioned or violated by the state.-- Remarks at the International Convention of B'nai B'rith, 6 September 1984