No evidence! Let me give you an example or two: A main founder of the ACLU, Roger Baldwin and his compatriot Emma Goldman (an Anarchist). Roger Baldwin embraced, initially, Communism. He only denounced the methods, not the concepts. The concepts of Communism include Atheism and Marxist statements that "Religion is the opiate of the People". Here is one of his statements: I am for socialism, disarmament, and, ultimately, for abolishing the state itself... I seek the social ownership of property, the abolition of the propertied class, and the sole control of those who produce wealth. Communism is the goal. Roger Nash Baldwin Article from Soviet Russia Today [edit] "Freedom in the U.S.A. and the U.S.S.R." (PDF document) (Soviet Russia Today, September 1934) [emphasis below in original] • I believe in non-violent methods of struggle as most effective in the long run for building up successful working class power. Where they cannot be followed or where they are not even permitted by the ruling class, obviously only violent tactics remain. I champion civil liberty as the best of the non-violent means of building the power on which workers rule must be based. If I aid the reactionaries to get free speech now and then, if I go outside the class struggle to fight against censorship, it is only because those liberties help to create a more hospitable atmosphere for working class liberties. The class struggle is the central conflict of the world; all others are incidental. • When that power of the working class is once achieved, as it has been only in the Soviet Union, I am for maintaining it by any means whatever. Dictatorship is the obvious means in a world of enemies at home and abroad. I dislike it in principle as dangerous to its own objects. But the Soviet Union has already created liberties far greater than exist elsewhere in the world. They are liberties that most closely affect the lives of the people — power in the trade unions, in peasant organizations, in the cultural life of nationalities, freedom of women in public and private life, and a tremendous development of education for adults and children. So, we see that Roger Baldwin was "anti-Religion' and anti-private property. Let's look at Emma Goldman's statements and sentiments: “The philosophy of Atheism represents a concept of life without any metaphysical Beyond or Divine Regulator. It is the concept of an actual, real world with its liberating, expanding and beautifying possibilities, as against an unreal world, which, with its spirits, oracles, and mean contentment has kept humanity in helpless degradation.” ― Emma Goldman, Anarchism and Other Essays “Anarchism stands for the liberation of the human mind from the dominion of religion and liberation of the human body from the coercion of property; liberation from the shackles and restraint of government. It stands for a social order based on the free grouping of individuals…” ― Emma Goldman, Anarchism and Other Essays “Religion, the dominion of the human mind; Property, the dominion of human needs; and Government, the dominion of human conduct, represent the stronghold of man's enslavement and all the horrors it entails.” ― Emma Goldman “I do not believe in God, because I believe in man. Whatever his mistakes, man has for thousands of years been working to undo the botched job your god has made.” ― Emma Goldman So, both were "anti-religion" and wanted to displace a Constitutional Republic with Communism or "communist concepts" or with anarchy (and we know what ends ancient Greece came to). These are the "seeds" of the ACLU and its stances on many issues of "religion and the public square" (which is a 20th century, Progressive phenomenon not grounded in the Founding documents). The "Separation Clause", as interpreted by the ACLU and others, is so far from the intent of the letter from the Danbury Baptists which denounced a governmental body favoring one denomination over another, not banning all religious speech and statements in the public domain.