In 2006, Jackley was recommended by U.S. Senator John Thune to replaced James E. McMahon and later nominated by President George W. Bush to be United States Attorney for the District of South Dakota. Later in 2006, Jackley was unanimously confirmed by the U.S. Senate. Marty was named the South Dakota Prosecutor of the Year in 2008 from the South Dakota State’s Attorneys Association. Jackley was succeeded as U.S. Attorney by Brendan Johnson.
Jackley received the Justice Management Institute Award for Excellence. Marty also served as Chairman of the Conference of Western Attorneys General and Vice-Chairman of the National Association of Attorneys General.
President of National Association of Attorneys General
Jackley was the first South Dakota Attorney General elected President of the National Association of Attorneys General and the theme of his tenure was "Policing in the 21st Century".
''South Dakota v. Wayfair''
Jackley appeared on behalf of the State of South Dakota in front of the United States Supreme Court in South Dakota v. Wayfair, Inc. on April 17, 2018. The state of South Dakota was represented at oral arguments by Jackley, and Deputy Solicitor General Malcolm L. Stewart. The Court agreed to hear the case in January 2018, with arguments heard on April 17, 2018 and a ruling expected by June at the end of the current term. The court held by a 5–4 majority that states may charge tax on purchases made from out-of-state sellers, even if the seller does not have a physical presence in the taxing state. The decision overturned Quill Corp. v. North Dakota, which had held that the Dormant Commerce Clause barred states from compelling retailers to collect sales or use taxes in connection with mail order or Internet sales made to their residents unless those retailers have a physical presence in the taxing state.
Political career
Rounds appointed Jackley to succeed Larry Long as Attorney General of South Dakota in 2009. Jackley won reelection in 2010 and in 2014. In 2018, Jackley unsuccessfully ran for Governor of South Dakota in the June primary, losing to U.S. Representative Kristi Noem.
Life after Attorney General
Marty rejoined the firm of Gunderson, Palmer, Nelson and Ashmore and opened up a law office in Pierre, South Dakota. On August 27, 2019, Marty was sworn in as the Jones County States Attorney.
Personal life
Marty lives in Pierre, South Dakota with his two children, Michael and Isabella. On October 18, 2019, Marty and Angela were divorced citing irreconcilable differences.