James Loeffler is a Senior Fellow of the Kogod Research Center at the Shalom Hartman Institute of North America and the Felix Posen Professor of Modern Jewish History and Department of History Director, Leonard and Helen R. Stulman Program in Jewish Studies, at Johns Hopkins University. His current research explores the ties between law and politics in twentieth- and twenty-first century Eastern Europe and the United States, with a focus on human rights, Jewish political thought, and antisemitism.

He is the author of the award-winning books Rooted Cosmopolitans: Jews and Human Rights in the Twentieth Century (2018) and The Most Musical Nation: Jews and Culture in the Late Russian Empire (2010), and two edited volumes, The Law of Strangers: Jewish Lawyers and International Law in the Twentieth Century (2019) and A Jew in the Street: New Views on European Jewish History (2024). He recently completed a four-year term as co-editor of the Association for Jewish Studies Review.

At present he is writing a book entitled Exceptional Hatred: Antisemitism and Free Speech in Modern America, the first historical study of how American constitutional law handles the problem of antisemitic hate speech, the book grows out of his reporting for The Atlantic magazine on the 2021 trial of White Supremacist leaders behind the deadly 2017 “Unite the Right” event in Charlottesville, Virginia.

He is also at work on a biography of Raphael Lemkin, the father of the Genocide Convention. That research traces the origins of the concept of genocide to the struggle for Jewish rights in pre-Holocaust Eastern Europe. It features newly discovered Hebrew and Yiddish writings, which are available at The Lemkin Project: A Digital Archive of Law, Literature and Global Thought.

Another area of research is the history of Zionism, in which he has published multiple studies on Zionism and liberal internationalism, and Zionism and Jewish culture. He is part of an international team researching the life and work of pioneering musician and scholar Avraham Zvi Idelsohn conducted under the auspices of the Jewish Music Research Centre at the Hebrew University of Jerusalem. This work can be found at The Idelsohn Project: A Digital Humanities Historical Initiative.

He earned his BA in Social Studies from Harvard University and received his MA and PhD with distinction in Jewish History from Columbia University, with postgraduate studies at the Pardes Institute and the Hebrew University. He has served as Dean’s Visiting Scholar at Georgetown University Law Center, Kluge Fellow at the Library of Congress, and Robert A. Savitt Fellow at the United States Holocaust Memorial Museum.

He lives in Washington, DC with his wife and children.