Miller-Rose Initiative Database

Welcome to the Miller-Rose Institute Initiative Database. This database provides information on all statewide initiatives adopted by voters in the United States from the first successful statewide initiative in 1904 through 2020. It allows users to sort voter-approved initiatives by year, state, subject category, and more, and to export data in a variety of forms to meet their research needs.

Originally developed by Dr. Ken Miller of Claremont McKenna College and student researchers as the empirical basis for Dr. Miller’s book Direct Democracy and the Courts, the database supplements the book and provides a resource for researchers and others interested in the development and use of the initiative process. The database is maintained at the Rose Institute of State and Local Government in Claremont, CA.

Post-election Challenges to Initiatives

The database also provides a unique source of information on post-election legal challenges to voter-approved initiatives. Users can view the challenges to a particular initiative by navigating to the “Details” page of that initiative or by accessing the aggregated table of all post-election challenges.  The data tables provide the case’s name and citation, court (state or federal), basis for the challenge, and outcome.

We regularly update this research and invite information about post-election challenges to initiatives in these states. You can contribute to this project by informing us about cases challenging voter-approved citizen initiatives.

If you have any questions on the database, please contact Dr. Miller at