After law school, Sauer was a
law clerk to Judge
J. Michael Luttig of the
U.S. Court of Appeals for the Fourth Circuit from 2004 to 2005 and to U.S. Supreme Court justice
Antonin Scalia from 2005 to 2006. He was in private practice at the law firm
Cooper & Kirk from 2006 to 2008, then became an
assistant United States attorney for the
Eastern District of Missouri. In the spring semesters between 2011 and 2013, he was an
adjunct professor at the
Washington University in St. Louis's law school. He later reentered private practice. Prosecutors dropped all charges against the priest, whose record had been fully
expunged as of June 17, 2015. Sauer prevailed in the civil lawsuits related to the accusations. On December 10, 2020, as Solicitor General Counsel of Record, Sauer signed the "Motion of States of Missouri, Arkansas, Louisiana, Mississippi, South Carolina, and Utah to Intervene and Proposed Bill of Complaint in Intervention" in an
attempt to overturn the 2020 United States presidential election. The motion sought to intervene and join the
Texas Bill of Complaint—filed by Texas attorney general
Ken Paxton—to prevent the selection of presidential electors based upon the November election results in Pennsylvania, Georgia, Wisconsin, and Michigan. In January 2023, Missouri attorney general
Andrew Bailey appointed Sauer
Deputy Attorney General for Special Litigation. Sauer resigned from his post less than a month later, on January 27, 2023. In July 2023, Sauer testified before the
United States House Judiciary Select Subcommittee on the Weaponization of the Federal Government as Louisiana Department of Justice Special Assistant Attorney General.
Representing Donald Trump On January 9, 2024, Sauer appeared before a panel of the
US Court of Appeals for the District of Columbia Circuit to argue on behalf of former president
Donald Trump regarding his presidential
immunity dispute. Trump's immunity dispute was a component of
United States of America v. Donald J. Trump, the federal criminal case concerning Trump's obstruction of the 2020 US presidential election. At the hearing, in response to a hypothetical question posed by Judge
Florence Y. Pan about whether a president could order
SEAL Team Six to assassinate a political rival and be immune from prosecution, Sauer argued that the impeachment clause in
Article II § Section 4 of the
US Constitution implies that the
US Senate must first impeach and convict an accused president before they can be criminally prosecuted, and that acquittal bars prosecution. Sauer further stated that should the court accept the United States' position regarding the (lack) of presidential immunity, it "would authorize, for example, the indictment of
President Biden in the Western District of Texas after he leaves office for mismanaging the border allegedly".
U.S. solicitor general In November 2024,
President-elect of the United States Donald Trump announced that he would nominate Sauer to serve as
Solicitor General of the United States. His nomination was confirmed by the US Senate on April 4, 2025, by a vote of 52–45. He took office the same day. In May 2025, Sauer asked the US Supreme Court to include the
Department of Government Efficiency as a "presidential advisory body" within the
Executive Office of the President. In the same month, during oral arguments in
Trump v. CASA which concerned
nationwide injunctions, Sauer informed the Supreme Court—regarding decisions from
United States circuit courts—that the executive branch "generally respect[s] circuit precedent, but not necessarily in every case". On April 1, 2026, Sauer presented arguments to the Supreme Court arguing that
birthright citizenship in the United States does not extend to children born in the United States because their parents are unlawfully present or in the country on temporary visas. Sauer argued that the Court faces a “new world” where "billions" are a plane ride away from obtaining US citizenship for their children. Chief Justice
John Roberts responded with: “It’s a new world. It’s the same Constitution." == See also ==