Overview

Background

Sauer was born November 13, 1974, in St. Louis, Missouri. He graduated from Duke University with a Bachelor of Arts in philosophy and a Bachelor of Science in electrical engineering, then attended Oriel College at the University of Oxford on a Rhodes Scholarship. He also earned a Master of Arts in philosophy from Notre Dame before completing his legal education. Sauer is a magna cum laude graduate of Harvard Law School.

He served as a law clerk to Justice Antonin Scalia of the U.S. Supreme Court. He then served as an Assistant U.S. Attorney in the Eastern District of Missouri from January 2008 to January 2013, before transitioning to private practice. After leaving Missouri's solicitor general office, Sauer formed his own law firm, the James Otis Law Group.

He served as Solicitor General of Missouri from 2017 to 2023. That tenure was politically significant: as solicitor general of Missouri, Sauer sought to overturn the 2020 United States presidential election. During his time at the Missouri Attorney General's office, he also led litigation involving Planned Parenthood and defended the state's effort to revoke the license of Missouri's only abortion clinic. The record established Sauer as a conservative litigator willing to take on high-profile, ideologically charged cases.

In 2024, when he was a private practicing attorney, Sauer represented Trump in Trump v. United States, which revolved around whether the Department of Justice could prosecute Trump for the January 6 insurrection and attempts to overturn the 2020 election. He successfully argued that the president has criminal immunity for any official actions taken while in office and a presumption of criminal immunity for anything on the periphery of official conduct. That victory established the relationship that led directly to his nomination as solicitor general.

Public Role in the Second Trump Administration

Confirmation and the Conflict-of-Interest Question

Sauer was nominated to the solicitor general position by Trump in November 2024. Since Trump's return to office in January, Sarah M. Harris had served as acting solicitor general while Sauer's confirmation was pending. Even before taking office formally, between his nomination and his confirmation, Sauer filed two briefs on behalf of Trump personally at the Supreme Court — one requesting the justices halt Trump's sentencing in his hush money case, and another requesting the justices halt the federal law that sought to ban TikTok. Multiple constitutional law commentators raised concerns about these actions, with one scholar arguing they could inflict long-term harmful effects on the government's relationship with the Court.

Expanding Executive Power

In Trump's second term, Sauer has argued in seven of the administration's biggest cases, ranging from the president's tariffs, challenged in Learning Resources, Inc. v. Trump, to his attempt to fire Federal Reserve Chair Lisa Cook, challenged in Trump v. Cook. As solicitor general, Sauer also argued in front of the Supreme Court to include the Department of Government Efficiency as a "presidential advisory body" within the Executive Office of the President.

On tariffs, Sauer presented the government's case in sweeping terms, warning of "ruthless trade retaliation" and "ruinous economic and national security consequences" if the Court struck down Trump's tariffs. He faced considerable skepticism from justices for his assertion of unilateral tariff power, yet key justices also poked holes in the challengers' arguments. Sauer is so favored by the president that when he lost the tariff case, a livid Trump publicly blamed the loss on the justices at a White House news conference with his solicitor general present.

Birthright Citizenship

The most watched case of Sauer's tenure involved the administration's effort to restrict birthright citizenship. The policy, which Trump signed the day he was inaugurated for his second term, would deny citizenship to children born in the U.S. to parents who are in the country illegally or temporarily, in a move that challenges long-standing interpretations of the 14th Amendment. Sauer urged the justices to review a ruling by a federal appeals court holding that the order violates the Constitution.

During oral argument, Sauer avoided the racial implications of the executive order, focusing instead on questions of the "domicile" and "allegiance" of the parents of children born in the United States. Sauer argued that birthright citizenship was meant to grant citizenship to formerly enslaved families alone — not to temporary visa holders or noncitizens who entered the U.S. illegally. The reception at the Court was skeptical. Chief Justice John Roberts characterized Sauer's examples from history as "quirky," and Justice Elena Kagan called his theory "revisionist." Kagan also noted that the Trump administration had been "losing uniformly" in lower court cases on the substantive question.

The Supreme Court ultimately rejected Trump's executive order, ruling that it ran afoul of the Constitution's 14th Amendment, which has long been interpreted to bestow birthright citizenship on almost anyone born in the United States.

Recent Developments

Sauer has become Trump's favored litigator after securing victories on issues such as presidential immunity and limiting the power of judges to block his policies nationwide. His mixed record — a landmark win on immunity, a loss on tariffs, a loss on birthright citizenship — reflects the range and ambition of the administration's legal agenda, which has tested constitutional limits across multiple domains simultaneously. The breadth of the docket Sauer manages is itself notable: he has overseen challenges to birthright citizenship, fast-track deportation authority, defunding of federal grants, and the removal of civil service protections for thousands of government workers.

Sauer's close alignment with the president has attracted scrutiny that would be unusual for a solicitor general in prior administrations. Critics have pointed to the dual role he played as Trump's personal criminal defense attorney and then as the government's chief Supreme Court advocate, arguing the transition blurred the line between representing a client and representing the public interest. Democrats objected during confirmation that Sauer would not clearly commit to following court orders — a concern that, in the context of the administration's broader tensions with the judiciary, carried particular weight.

Outlook

Sauer's name is also frequently mentioned as a possible Supreme Court nominee should a vacancy arise. Trump's outside legal adviser Mike Davis has said that Sauer "has been so effective for President Trump, both as his defense attorney and as a solicitor general," describing him as "certainly at the top of my short list for the Supreme Court." Whether that prospect materializes depends on Court vacancies and political timing, but it signals Sauer's standing within the Trump orbit as someone whose influence is not limited to his current role.

As solicitor general, Sauer remains the administration's principal advocate before the Supreme Court at a moment when the executive branch is seeking to reshape the boundaries of presidential power more aggressively than at any point in recent history. His record so far — credentialed, ideologically committed, and personally aligned with the president — suggests he will continue pressing ambitious constitutional claims regardless of the odds, with the most consequential outcomes likely still ahead as the Court addresses further aspects of the administration's agenda in subsequent terms.