Carpenter received his B.A. in history, magna cum laude, from Yale University in 1989. He earned his Juris Doctor, with honors, from the University of Chicago Law School in 1992, where he served as editor-in-chief of the University of Chicago Law Review.
After law school, Carpenter was a law clerk to the Hon. Edith H. Jones of the United States Court of Appeals for the Fifth Circuit, from 1992 to 1993. He next began work as an attorney at Vinson & Elkins in Houston, Texas and Howard, Rice, Nemerovski, Canady, Falk & Rabkin in San Francisco, California and is a member of the state bars of Texas and California. Carpenter was the president of the Log Cabin Republicans of Texas in 1996-97.
Carpenter is a libertarian-leaning conservative. He is noted for his scholarship on same-sex rights in the United States. He co-authored an Amicus brief for Lawrence v. Texas (2003) on behalf of the Republican Unity Coalition, a gay-straight Republican organization.
He was the Julius E. Davis Professor of Law for 2006-07 and the Vance K. Opperman Research Scholar at the University of Minnesota Law School for 2003-04. Professor Carpenter was chosen the Stanley V. Kinyon Teacher of the Year for 2003-04 and 2005-06 and was the Tenured Teacher of the Year for 2006-07. Since 2004, he has served as an editor of Constitutional Commentary.
In 2007, he was appointed to the Earl R. Larson Chair in Civil Rights and Civil Liberties Law. He received both the D. Francis Bustin Prize for excellence in legal scholarship and the John M. Olin Foundation Scholarship for Law & Economics.
He is a member of the state bars of Texas and California. As a professor, he specializes in constitutional law, the First Amendment, sexual orientation and the law, and commercial law.
Carpenter is a frequent speaker on issues surrounding same-sex marriage. Outside of traditional legal academia, he also writes a regular column, "OutRight", for several gay publications across the United States. He is a regular contributor to the Independent Gay Forum as well as the weblog "The Volokh Conspiracy" and is regularly cited in the American media.