So you believe it would be acceptible to teach that the universe has no design?
because most people don't want it to be part of such a classroom.
I don't believe that to be true. The only way to test it would be to put it to a vote with the understanding that the vote would be meaningful.
If it were true that most Americans would not accept that our rights are endowed by a creator, that's pretty much the end for us.
Why would anyone object to teaching this as a universal axiom applicable to the entire curriculum? It wouldn't have any affect on any science class since I think we all agree that science is incapable of addressing the question of God's existance.
I think we should teach what we know in science classes, based on the best available scientific evidence. Right now, that's the neo-Darwinian synthesis. If and when there is compelling scientific evidence to indicate design, whatever that might consist of, then we should teach that, but unless and until that happens, there's nothing there to teach yet, and so science curricula should be silent on the issue for the time being. Because of that, and because there's no agreement on what sort of creationism to teach, there's really just not a large-scale grass-roots effort to teach creationism in science class. That movement simply doesn't exist - people would rather deal with it in other ways besides sticking it into the public schools. Instead, what you have is a relatively small group of dedicated activists trying to slip it in through the back door.
Besides, why would you want the public schools teaching ID or creationism? They'll just butcher it, you know - I assure you, they are complete failures at really teaching evolution well, and I see no reason to expect they'll do a better job with something else. Hell, they can barely teach kids to read in a lot of places - why on earth would you think that ID theory will get a good treatment?
If it were true that most Americans would not accept that our rights are endowed by a creator, that's pretty much the end for us.
It's not a matter of not accepting that to be true - the vast majority of Americans do accept that to be true. What there is much less agreement on is how God figures into the development of life. And because there's a good deal of disagreement, the only thing you'll get people to agree on putting into a science class will be something so bland and watered-down that it might as well not be there at all. It's the same problem you have when ordering three pizzas for twenty random people - the only way you're likely to get agreement on what kind of pizzas to get is if they're pretty plain.
Why would anyone object to teaching this as a universal axiom applicable to the entire curriculum?
Because most people are satisfied with the status quo, and see no incentive to change, particularly when the change requires a large-scale rewrite of constitutional law.