Mr. Shackelford is a constitutional scholar who has argued before the United States Supreme Court, testified before the U.S. House and Senate on constitutional issues, and has won three state landmark First Amendment and religious liberty cases in the past few years alone. He was recently named one of the 25 greatest Texas lawyers of the past quarter-century by Texas Lawyer, and is the recipient of the prestigious William Bentley Ball Award for Life and Religious Freedom Defense for his leadership and pioneering work protecting religious freedom.

Jeff Mateer is the Chief Legal Officer of First Liberty Institute, where he serves as a member of the executive leadership team and oversees and directs First Liberty’s legal operations, including its litigation, media/communications, and external affairs teams. He rejoined First Liberty Institute in October 2020 after serving as First Assistant Attorney General of Texas from March 2016 through October 2020.

Jeff has served in the legal field for over 30 years, and in addition to having received an A-V rating by Martindale-Hubbell, Jeff has been honored as a Texas Rising Star and Texas Super Lawyer. He received his undergraduate education at Dickinson College, where he graduated with honors in 1987, and his legal education at Southern Methodist University, where he graduated with honors in 1990. While in law school, he served as an editor of the law review. He is licensed to practice law by the state of Texas and is admitted to practice before all Texas State and Federal District Courts, the 2nd, 4th, 5th, 7th, 9th and 11th U.S. Circuit Court of Appeals, and the United States Supreme Court.