The call to prayer is sounding across America. From Hamtramck, Michigan, to Paterson, New Jersey, to Minneapolis, Minnesota, rooftop amplifiers remind growing numbers of Muslim faithful five times a day of their duties with the Arabic message that “Allah is the Greatest! There is no god but Allah!”

In what they hope will become a hot-button election issue in the November midterms, congressional Republicans unnerved by the spread of Islam are holding hearings and proposing legislation to prevent immigrants who adhere to “Sharia law” from entering or staying in the U.S.