Professor of Law at the University of New South Wales.  Before relocating to Australia in January 2009, he was (for four years) the founding director of the South African Institute for Advanced Constitutional, Public, Human Rights and International Law (SAIFAC), an independent research centre based on Constitution Hill, Johannesburg.

His main research interest is in comparative constitutional law, focusing on the politics of judicial review in new democracies.  He is a former Secretary-General of the International Association of Constitutional Law, and co-editor of the major loose-leaf commentary on South African constitutional law, Stuart Woolman et al Constitutional Law of South Africa. In addition to his academic work, he has acted as a consultant to the South African government in the areas of land restitution, land tenure reform, and regulation impact analysis.