Previous research examining the impact of extra-Court factors on Supreme Court decision making has developed conflicting theoretical perspectives supported with limited empirical evidence. In an attempt to better assess the influence of Congress on Court decisions, we develop a theoretical model specifying the conditions under which congressional preferences might constrain justices’ votes on the merits. More specifically, we argue that previous congressional overrides in an issue area and case-level interest group activity make congressional preferences salient for the justices. In these threat situations, the justices will be most likely to shift their final votes on the merits in a manner congruent with the preferences of Congress. Based on our logit analysis of data on all orally argued statutory cases from 1963 to 1995, we find mixed support for our hypotheses and conclude that there are limited conditions under which congressional preferences may influence a justice’s vote.