There are two sides to this, regardless of your opinion on one's validity. The point is that people pay to send their kids to these schools and ultimately should have the say on these things, and not just in a distant representative kind of way (though that's barely happening now).
How's this for fair: When the government makes church service mandatory, you can start asserting that Darwinism should be expounded from the pulpit.
Whatever you say.
But when conservatives can no longer be elected because a plurality thinks they're owned by the fundamentalist Christian denominations, don't come crying on my shoulder.
If destroying the validity of science is your top, number 1 goal and you're willing to expend all our political capital on the effort. Fine.
But the effort is doomed to failure, and the attempt itself will preclude any other conservative measures for a generation.
Creationism is not only scientifically ignorant. It's politically ignorant as well.