That may be YOUR claim, but show me where the ACLU states that position.
I can start with the fact that the ACLU was founded by communists, who are anti-Christian.
But look at who whines the most about any display of Christianity in public? It is always the ACLU. Any time a town wants to put up a manger in public the ACLU is the first to whine, even if other religions get to put up their own religious displays in public. Why does the ACLU believe that Christians should be treated as second class citizens in that we cannot put up a religious display in public but other religions can?
Let's look at another related issue. Any time someone whines about the 10 Commandments being displayed in a courthouse, even though they do not compel anyone to believe, and even though they are the basis for all of our own secular law, the ACLU is the first to whine. We've seen this happen all over the country. What more proof do you need?