The Chicago Sun-Times is reporting that conservative columnist Robert Novak has announced his immediate retirement. He told the paper that his recent diagnosis of a brain tumor was “dire.” Novak was involved in an accident on July 23 when he hit a pedestrian with his car and drove away. He was stopped a short distance later by a bicyclist who witnessed the incident. Novak claimed he didn’t realize he had hit someone. He was diagnosed with a brain tumor the following Sunday, July 27.