An unusually deep record of Duncan's views on First Amendment issues is available. From 2004-2008, he was an Assistant Professor of Law at the University of Mississippi where he taught courses on constitutional law, church-state relations, and free speech. (Bio.) Duncan's publications include:
- Secularism's Laws: State Blaine Amendments and Religious Persecution, 72 Fordham L. Rev. 493 (2003).
- Bringing Scalia's Decalogue Dissent Down from the Mountain, 2007 Utah L. Rev. 287 [LEXIS link].
- Prosecution Responses To Internet Victimization: Child Pornography and First Amendment Standards, 76 Miss. L. J. 677 (2007).
- Subsidiarity and Religious Establishments in the United States Constitution, 52 Vill. L. Rev. 67 (2007).
- Misunderstanding Freedom from Religion: Two Cents on Madison's Three Pence, 9 Nev. L.J. 32 (2008).
From 2012- 2014 Duncan served as general counsel for the Becket Fund for Religious Liberty. He was lead counsel in the Supreme Court case of Hobby Lobby Stores v. Burwell which concluded that the Affordable Care Act's contraceptive coverage mandate violates religious rights of objecting small businesses under RFRA. Here is the merits brief that Duncan's team filed in the case.
Now a partner in the Washington, D.C. law firm of Scherr Duncan, his web page includes links to nearly a dozen news interviews and blog posts in which Duncan talks about religious liberty issues.