conservatives have just never gotten over this idea that humans aren't property. your kids have rights, including the right to an education, and if you're going to warp that to the point that it's no longer recognizable then the government has a responsibility to step in and uphold the kids' right. this idea that you have the right to imprint your own beliefs in your kids is incoherent within any consistent rights theory. it's just a lingering remnant of chattel slavery.