20 U.S.C. § 67 — Right of repeal

This section reserves Congress's power to change an earlier law, while protecting rights already created under it. Congress may alter, amend, add to, or repeal any of the provisions of sections 41 to 46, 48, 50, 51 to 53, and 54 to 57 of this title. But there's a limit: no contract or individual right that was already made or acquired under those provisions can be divested (taken away) or impaired (weakened) just because Congress changes the law.