Under the Federal IndividualswithDisabilitiesEducationAct, states cannot cut existing services to special needs students, even if federal funding bottoms out.
Federal regulations enacted under the IndividualswithDisabilitiesEducationAct require schools to develop individualized education programs (IEP) for children who are classified as students withdisabilities.
There is a precedent of sorts set by the Supreme Court-approved IndividualswithDisabilitiesEducationAct, under which schools that don't provide disabled students with an "appropriate" education are required to pay their tuition in private schools.