You'd have to consult an attorney for a thorough answer, but my understanding is that US federal law requires public school districts (K-12) to provide an education for every eligible child. The ADA applies to children with disabilities, and districts must provide their special educational needs as much as can be done (there are limits of course but expectations are high).

Schools often don't look for kids who need beyond average services, and may defer, even resist doing so unless parents make a point of pushing the issue. I've known parents who have taken schools to court to get cooperation. Too bad that's necessary, schools invariably relent. It is the law.

Basic education is a right, and you have the freedom to pursue advanced education, often subsidized by the government.

Do you feel like you have a right to the same education as the best-educated person? I don't.

Why should they?

Education isn't a right. It is a choice.