The big question is who pays the ACLU legal fees.
We do.
A Federal law provides that the judge in a civil rights suit can direct the Federal Government (that is, you and me) to reimburse the legal fees of a winning plaintiff. The ACLU has benefited from this many times.
Any time the ACLU takes up a "civil rights" case, the taxpayer gets soaked to pay them. Almost everything the ACLU files is a "civil rights" action designed to keep their lawyers sucking at the taxpayers tit. They win often enough to keep doing it.