Federalist No. 51 can be read as a statement of the national government’s dual responsibility to serve the public interest and to preserve liberty. It is built on James Madison’s belief in checks and balances as a method for keeping government’s parts in their proper places. This essay asks whether this gridlock has gone too far in rendering the constitutional design obsolete. Drawing on previously unpublished fragments of Federalist No. 51, the author argues that Madison fully anticipated these problems, and he offers the unpublished text as a salutary appendix to this iconic defense of liberty.