You are wrong. ACLU lawyers are mostly private lawyers (sometimes lawschool professors) who do part time work for the ACLU pro bono.
ACLU attorneys risk not being paid only in cases they lose. In cases where a citizen establishes that government action infringed upon a protected right, his attorney fees and court costs are assessed against the losing government unit.
-most importantly they are leftist morally devoid communists -Satan works "pro bono" as well...