On May 10, 2018, President
Donald Trump withdrew Nelson's nomination to be Solicitor of the Department of the Interior and announced his intent to instead nominate him to serve as a
United States circuit judge of the
United States Court of Appeals for the Ninth Circuit. On May 15, 2018, his nomination was sent to the
Senate. Nelson was nominated to the seat vacated by Judge
N. Randy Smith, who subsequently assumed
senior status on August 11, 2018. On July 11, 2018, a hearing on his nomination was held before the
Senate Judiciary Committee. On September 13, 2018, his nomination was reported out of committee by an 11–10 vote. On October 11, 2018, the
United States Senate confirmed his nomination by a 51–44 vote. He received his judicial commission on October 18, 2018. In 2025, amid
deployments of National Guard into cities across the United States by the second Donald Trump administration, Nelson questioned whether the judiciary can restrain the president from deploying the National Guard in this manner. == Memberships ==