Barron joined the Harvard Law School faculty as an assistant professor in 1999 and became a professor in 2004. He left the faculty upon his confirmation to the Court of Appeals in 2014.[3][2]
In 2009, while on leave from his faculty position, Barron rejoined the Office of Legal Counsel as Acting assistant attorney general. In 2010, he authored a secret memo which provided the legal foundation for President Obama's unprecedented decision to order a drone strike on Anwar al-Awlaki, an American citizen who was a radical Islamic militant living in Yemen.[4] Barron's memo was described by The New York Times Editorial Board as "a slapdash pastiche of legal theories—some based on obscure interpretations of British and Israeli law—that was clearly tailored to the desired result."[5] A lawyer for the ACLU described the memo as "disturbing" and "ultimately an argument that the president can order targeted killings of Americans without ever having to account to anyone outside the executive branch."[6]
Barron returned to the Harvard Law School faculty in 2010 and was named the S. William Green Professor of Public Law in 2011. In 2012, he was appointed by Massachusetts Governor Deval Patrick to the Massachusetts Board of Higher Education.[7] and the Massachusetts State College Building Authority.[2] He left academia in 2014 after his confirmation as a federal judge.[3]
On September 24, 2013, President Barack Obama nominated Barron to serve as a United States Circuit Judge of the United States Court of Appeals for the First Circuit, to the seat vacated by Judge Michael Boudin, who assumed senior status on June 1, 2013.[9] On January 16, 2014, his nomination was reported out of committee by a 10–8 vote.[10] On Thursday, May 15, 2014, Senate Majority Leader Harry Reid filed a motion to invoke cloture on the nomination. On Wednesday, May 21, 2014, the United States Senate invoked cloture on his nomination by a 52–43 vote.[11] Several senators, including Mark Udall (D) and Rand Paul (R), pledged to oppose Barron's nomination unless the administration publishes the secret memos Barron authored on the legality of killing American citizens with drone strikes.[12] Until senators began raising concerns about Barron's nomination, only those on the Judiciary and Intelligence committees had seen any of the classified memos.[13] On May 22, 2014, his nomination was confirmed by a 53–45 vote.[14] He received his judicial commission on May 23, 2014.[3] He became Chief Judge on April 1, 2022, when Judge Jeffrey R. Howard assumed senior status.[15]
Publications
Barron is known for coauthoring with Martin S. Lederman a Harvard Law Review article titled "The Commander in Chief at the Lowest Ebb - Framing the Problem, Doctrine and Original Understanding,"[16] which was an attack of the advice given by the Office of Legal Counsel to President George W. Bush justifying Bush's use of executive power during the War on Terror.[17]