What can the US Supreme Court change if it is unconstitutional?

Congress can attempt to rewrite the law so that it conforms with the Supreme Court's interpretation of the Constitution; or, they can abandon an ill-conceived law; or, they can attempt to work with the states to amend the Constitution (the least likely and most time-consuming solution). Congress cannot nullify the Supreme Court decision, however.

In most cases, they either rewrite or abandon the legislation.

judicial review (GradPoint)