Research on judicial independence suggests that high courts can be designed to serve as external checks on political actors. However, independence from political influence does not necessarily imply incentives to use these powers. Chile's Constitutional Tribunal, while possessing significant powers, has been characterized as generally deferential to political actors. Using rulings from the Tribunal from 1990–2010, we examine whether reforms that increased the number of judges appointed by politicians and expanded the Tribunal's jurisdiction have contributed to a more assertive use of judicial review power. We find that the reforms have not produced an increased tendency to rule laws unconstitutional under abstract review. However, the new appointment structure has nevertheless increased the types of judges relatively more likely to assert this power. Specifically, after the reforms, judges appointed by elected actors were individually more likely to find laws unconstitutional than those appointed by the Supreme Court, especially on cases of concrete review of enacted laws. We also find that cases of abstract review brought by legislators have been especially associated with both unconstitutional rulings and individual judicial votes for unconstitutionality.