Preuß (born on 6 December 1939) teaches Theories of the State at the Hertie School of Governance.
He holds a PhD from Gießen University and worked as Professor for Public Law at the University of Bremen from 1972 to 1996.
Since 1996, Preuß has been a Professor of Public Law and Politics at Freie Universität Berlin.
In 1989/90, he co-authored the draft of the constitution as a participant of the Round Table of the German Democratic Republic, and in 1992/93 he advised the Thuringian parliament on the conception of a new constitution.
He has taught (among others) at Princeton University, New School University, and the University of Chicago.
He is on the advisory board of various research institutions and is a member of the Staatsgerichtshof (State Supreme Court) in Bremen.