Congress enacted a statute authorizing the denial of all federal funding to public school districts in which a specified percentage of the students enrolled in the public schools fail to pass a national achievement test. According to the terms of the federal statute, the first national achievement test was scheduled for administration five years from the effective date of the statute. After reviewing then-current levels of public school student performance, the officials of a state became concerned that several of its public school districts would lose their federal funding after the administration of the first national achievement test. Then-current levels of private school student performance were substantially higher. In order to improve the chances of those school districts retaining their federal funding, the state recently enacted a law that requires all children of elementary and secondary school age to attend the schools operated by their respective local public school districts. The law is to take effect at the beginning of the next school year. Parents of children enrolled in private schools within the state have filed suit to challenge the constitutionality of this state law. Should the court uphold the law?