When conservatives took control of the federal judiciary in the 1980s, it was widely assumed that they would reverse the landmark rights-protecting precedents set by the Warren Court and replace them with a broad commitment to judicial restraint. Instead, the Supreme Court under Chief Justice William Rehnquist has reaffirmed most of those liberal decisions while creating its own brand of conservative judicial activism.

Ranging from 1937 to the present, The Most Activist Supreme Court in History traces the legal and political forces that have shaped the modern Court. Thomas M. Keck argues that the tensions within modern conservatism have produced a court that exercises its own power quite actively, on behalf of both liberal and conservative ends. Despite the long-standing conservative commitment to restraint, the justices of the Rehnquist Court have stepped in to settle divisive political conflicts over abortion, affirmative action, gay rights, presidential elections, and much more. Keck focuses in particular on the role of Justices O'Connor and Kennedy, whose deciding votes have shaped this uncharacteristically activist Court.