You clearly do not live in the Pacific Northwest.
What would make an impact is a refusal to pay school taxes. Let it be just a one time thing to catch the attention of the media—and the school board. But enough people have to be involved to make the amounts large enough to care about. I think this is called civil disobedience.
I’m in the Pacific Northwest and homeschooling’s the only option good enough for my kiddos. It’s not so much the lack of God, although that’s a serious concern, it’s my desire to see them fully educated.