Recent scholarship suggests that the U.S. Supreme Court might be constrained by Congress in constitutional cases. We suggest two potential paths to Congressional influence on the Court's constitutional decisions: a rational-anticipation model, in which the Court moves away from its preferences in order to avoid being overruled, and an institutional-maintenance model, in which the Court protects itself against Congressional attacks to its institutional prerogatives by scaling back its striking of laws when the distance between the Court and Congress increases. We test these models by using Common Space scores and the original roll-call votes to estimate support in the current Congress for the original legislation and the Court's preferences over that legislation. We find that the Court does not appear to consider the likelihood of override in constitutional cases, but it does back away from striking laws when it is ideologically distant from Congress.