...Yesss! Free debate, ...in the schools, where only one orthodoxy can present its materials!!!
"Free debate" ---Stalin-style!
I'm not sure high schools have the capability to teach kids about evert existing theory in every scientific or scholastic field. Given the limited nature of high school education, the schools should stick with teaching the accepted theory in each field and leave the bigger debates for colleges. If the greater scientific community accepts a new theory in a particular field, the schools should teach that theory.
Not just in biology either. In chemistry class they teach matter is composed of atoms, and don't even look at alternative theories. In physics they teach Newton's laws as established fact. In French, they maintain that 'le mouton' is a sheep and not the alternative that it might be a cow.
Education is an authoritarian enterprise. The teacher knows better than the students. At least, that's the ideal. Your local school may vary.
Only one side of this debate has any materials to begin with. There is no scientific evidence that I am aware of that supports ID. If you know of any, please present it here in a format that would be accessible to your average high school student.