"The demand for a statement of a candidate’s religious belief can have no meaning except that there may be discrimination for or against him because of that belief. Discrimination against the holder of one faith means retaliatory discrimination against men of other faiths. The inevitable result of entering upon such a practice would be an abandonment of our real freedom of conscience and a reversion to the dreadful conditions of religious dissension which in so many lands have proved fatal to true liberty, to true religion, and to all advance in civilization."