On March 1, 2019, President Donald Trump announced his intent to nominate Downing to be the U.S. Attorney for the Western District of Oklahoma. On March 5, 2019, his nomination was sent to the United States Senate.[2] On May 9, 2019, his nomination was reported out of committee by voice vote.[3] On May 23, 2019, the Senate confirmed his nomination by voice vote.[4] He was sworn in on June 5, 2019.[5] On February 9, 2021, he announced his resignation, effective February 28, 2021.[6]