Query: Along with Stewart, what Supreme Court justice was concerned about racial disparity in death penalty enforcement?
Context: The narrowest opinions, those of Byron White and Potter Stewart, expressed generalized concerns about the inconsistent application of the death penalty across a variety of cases but did not exclude the possibility of a constitutional death penalty law. Stewart and William O. Douglas worried explicitly about racial discrimination in enforcement of the death penalty. Thurgood Marshall and William J. Brennan, Jr. expressed the opinion that the death penalty was proscribed absolutely by the Eighth Amendment as "cruel and unusual" punishment.