Bruce Ackerman, writing in the L.A. Times today:

In retrospect, Souter and Thomas have turned out very different. Souter has developed into a moderate conservative in the tradition of John Marshall Harlan, the great dissenter to many of the activist decisions of the Warren court, but a firm believer in the right to privacy and due process of law.

Thomas, in contrast, has established himself as the most reactionary jurist of the modern era. He is the only member of the high court who claims that the New Deal expansion of federal regulatory power was a "wrong turn," that the Constitution permits a state such as Utah to establish Mormonism as its religion, and that American citizens may be detained indefinitely on the say-so of the president.

Um, yeah, David Souter--definitely a "moderate conservative."

For the record, he labels O'Connor a "conservative pragmatist" which, from what I can gather, is somewhere between "moderate conservative" and "reactionary".