It has been said that American-style split sovereignty provides the people a “double security” for their liberties. And a distinct security too: where the Framers’ primary restraint on the avarice of the United States was the enumeration of its powers, each state is omnipotent and yet typically bound by a thicker conception of the proper ends of government. But these separate sovereigns interact in unique and sometimes puzzling ways that leave the state of the vertical separation of powers in flux. And given that “split[ting] the atom of sovereignty,” as Justice Kennedy characterized it in US Term Limits v. Thornton, is a uniquely American contribution, is it really necessary to secure the people’s liberty? Featuring Prof. Maureen Brady, Louis D. Brandeis Professor of Law and Deputy Dean, Harvard Law School Hon. Sarah K. Campbell, Justice, Tennessee Supreme Court Hon. James E. Tierney, Lecturer on Law, Harvard Law School and former Attorney General, Maine Prof. Ernest A. Young, Alston & Bird Distinguished Professor of Law, Duke University School of Law Moderator: Hon. Stephanos Bibas, Judge, United States Court of Appeals for the Third Circuit