Professor Lembcke is a professor of political science and teaches at the Ruhr University Bochum. From 2004 to 2013, he was Executive Director of the Hellmuth Loening Centre for Political Science, and since 2013 he has been a member of the Board of Directors. Since 2008, he has co-edited the POLITIKA series of the Mohr Siebeck publishing house with Rolf Gröschner.

He has also held professorships at the University of Leipzig, the University of Jena and the Helmut Schmidt University in Hamburg, and has been visiting professor at the University of Trier, the University of Erfurt, the University of Kiel and the Pedagogical University of Ludwigsburg. His research interests include modern democracy and its challenges, the relationship between the state, law, and injustice, and the history and impact of political ideas.