Heinz is the John and Rylla Bosshard Professor of Law and the Sheldon B. Lubar Distinguished Research Chair at the University of Wisconsin Law School, where he specializes in comparative constitutional law, socio-legal studies, and democratic transitions. Born and raised in Durban, South Africa, Klug was a prominent anti-apartheid student leader and spent eleven years in exile before earning his J.D. and S.J.D. from UC Hastings.
Returning to South Africa in 1990, he served as a member of the African National Congress (ANC) Land Commission and a researcher for the ANC Constitutional Committee, later contributing to the World Bank mission on land reform. He taught at the University of the Witwatersrand from 1991 to 1996 before joining the faculty at Wisconsin. His scholarship bridges empirical “law-in-action” frameworks with constitutional design, deeply informed by his firsthand involvement in post-apartheid political reconstruction.
He has authored seminal texts including Constituting Democracy: Law, Globalism and South Africa’s Political Reconstruction (2000) and The Constitution of South Africa: A Contextual Analysis (2008). His more recent work extends into modern legal realism and institutional resistance against authoritarian backsliding, with contributions featured in the collaborative volume Legal Resistance to Autocracy: The Global Fight to Save Democracy (Routledge, 2025).