Treatises & Hornbooks
Chemerinsky, Erwin. Constitutional Law: Principles & Policies. Aspen. 5th ed. 2015.
(Comment: Solid analysis and doctrinal presentation. Helpful particularly to those confused about case rulings and reasonings.)
Levy, Leonard, Kenneth Karst, and Dennis Mahoney, eds. Encyclopedia of the American Constitution. Macmillan and Free Press. 1986, 1992.
(Comment: Superb, sophisticated, but not relevant for more recent jurisprudence.)
Nowak, John, and Ronald Rotunda. Hornbook on Constitutional Law. West Publishing. 8th ed. 2010.
(Comment: More comprehensive than the Chemerinsky treatise, but even less theoretical. Not relevant for more recent jurisprudence.)
Tribe, Laurence. American Constitutional Law. Foundation Press.
Volume 1, 3rd ed., 2000 (Separation of Powers & Federalism)
Single Volume Treatise, 2nd ed., 1988 (Separation of Powers, Federalism, and Individual Liberties)
(Comment: Highly influential. First-rate liberal account, though complicated. The treatise is now dated in its treatment of individual rights, since Volume 2 was never completed.)
Readers & Anthologies
Carey, George W. A Student's Guide to American Political Thought. Intercollegiate Studies Institute. 2005.
(Comment: A compact and understandable primer providing a basic appreciation of constitutional history, structure, and theory - including the concerns of the Founding Era, contemporary issues of Federalism and Separation of Powers, and the notions of republicanism, limited government, and the problem of civic virtue.)
Garvey, John, T. Alexander Aleinikoff & Daniel A. Farber, eds. Modern Constitutional Theory: A Reader. West Publishing. 5th ed. 2004.
Gerhardt, Michael J., Steven Griffin, and Thomas D. Rowe, Rebecca L. Brown, and Girardeau A. Spann, eds. Constitutional Theory: Arguments and Perspectives. Carolina Academic Press. 4th ed. 2013.
Glennon, Michael J., Donald E. Lively, Phoebe A. Haddon, Dorothy E. Roberts, and Russell L. Weaver, eds. A Constitutional Law Anthology. Anderson. 2nd ed., 1997.
Barron, Jerome, and Thomas Dienes. Constitutional Law in a Nutshell. West Publishing. 8th ed. 2013.
(Comment: Good for a nutshell!)