Environmental regulation in the United States has increased pollution abatement expenditure as a percentage of gross national product from 1.7 percent in 1972 to an estimated 2.6 percent in the year 2000. This rise in regulation has coincided with demographic and economic changes that include rising educational levels, a growing minority population, an aging population, and decreasing employment in polluting industries. This paper examines whether these trends have contributed to increasing aggregate demand for environmental regulation. New evidence on voting on environmental ballots in California, local government environmental expenditures across the United States, and 25 years of congressional voting on environmental issues is examined to document the demographic correlates of environmental support. Minorities and the more educated are more pro-green, whereas manufacturing workers oppose environmental regulation. While demographics help explain observed differences in environmental support and thus can help predict long trends in the “average voter's” environmentalism, environmentalism varies substantially year to year unrelated to population demographics. © 2002 by the Association for Public Policy Analysis and Management.