You need to know that the ACLU can raise a lot of hell with a modest amount of money. "Vote with your money" means different things depending on the organization involved. The ACLU does not need more money than the government to win significant lawsuits.
Nevertheless, it does cost money, and not a pittance. Particularly since selecting the best cases usually means working pro bono. And teams of attorneys ain't cheap, and there's so much messed up in the United States that you've got to be able to field a bunch of those teams.
