On the high court, Justice Nix developed a reputation as a voice for individual rights. A champion of the broader rights accorded by the state constitution, Justice Nix led the court to interpret the Pennsylvania Constitution to ensure more individual rights than the U.S. Constitution, especially in the areas of search and seizure and sovereign immunity. He was also an early voice against prosecutors using their power to exclude African Americans from juries. Although generally considered a liberal, in 1977 he was the lone voice for upholding Pennsylvania's death penalty statute.