NOT a Religious test; rather a Political test
Beginning in 1938 we had a "House Committee on Un-American Activities," which sought out information on dissidents, of a political belief nature. It operated 1938 to 1975.
Earlier from 1919 sought information on Communists. There were other committees, as well.
I see Islam as a political system, more similar to Communism, and quite unlike most religious systems of the present day.
As such, intelligence on people advocating overthrow of our way of life, politically under the disguise of religion, ought to be fair game.
Hence I support classification of Islamic terrorists as political, not religious enemies of my country. Repeat:
Islamic terrorists are POLITICAL enemies of my country. Classify, list them, find them, expel, jail, kill them.
https://en.wikipedia.org/wiki/House_Un-American_Activities_CommitteeWe learned about Alger Hiss, by government interest in those that would do us harm.