The founding debate of judicial politics—is Supreme Court decision making driven by law or politics? —remains at center stage. One influential line of attack involves the identification of jurisprudential regimes, stable patterns of case decisions based on the influence of case factors. The key test is whether the regime changes after a major precedent-setting decision, that is, whether the case factors are subsequently treated differently by the Supreme Court justices themselves so that they vote as though constrained by precedent. We analyze whether binding jurisprudential regime change actually exists. The standard test assumes votes are independent observations, even though they are clustered by case and by term. We argue that a (nonparametric) “randomization test” is more appropriate. We find little evidence that precedents affect voting.