 Dennis has published op-ed articles in "The New York Times", "The Wall Street Journal", and the "Chicago Tribune".He is the president of the Dennis Trading Group Inc. and the vice-chairman of C&D Commodities, a former chairman of the advisory board of the Drug Policy Alliance, a member of the Board of Directors of the Cato Institute, and on the Board of Trustees of the Reason Foundation.He is a supporter of Flex Your Rights, a nonprofit organization that educates the public about their constitutional rights during police encounters.