By

Paula Reid
,

Casey Gannon

29 min ago

PUBLISHED Mar 31, 2026, 3:31 PM ET

Donald Trump Supreme Court

See all topics

Facebook Tweet Email Link Threads

Link Copied!

US Solicitor General D. John Sauer attends a press briefing held at the White House on February 20.

Aaron Schwartz/Getty Images/File

The Supreme Court on Wednesday will hear its biggest case of the term: about whether President Donald Trump’s effort to limit birthright citizenship through executive order is constitutional.

This case will not be easy to win – a ruling for Trump would upend a long-standing tenant of constitutional law and would have significant implications for US citizens who could face new hurdles documenting newborns.

The case will be argued by Solicitor General D. John Sauer, who has become Trump’s favorite litigator after securing historic victories on issues such as presidential immunity and limiting the power of judges to block his policies nationwide. Sauer’s name is also frequently mentioned as a possible Supreme Court nominee should a vacancy arise.

Related article People hold a banner as they participate in a protest outside the US Supreme Court over President Donald Trump’s move to end birthright citizenship on May 15, 2025. Jim Watson/AFP/Getty Images/File Parents fear their children born in the US could become ‘stateless’ if Trump wins birthright case 6 min read

“John Sauer has been so effective for President Trump, both as his defense attorney and as a solicitor general. He is certainly at the top of my short list for the Supreme Court,” said Trump outside legal adviser Mike Davis.

Sauer is so favored by the president that when he lost a case about Trump’s tariff policy earlier this year, a livid Trump publicly blamed the loss on the justices at a White House news conference with his solicitor general.

But the birthright citizenship case presents the biggest challenge yet for Sauer. Even some administration officials have privately admitted that the justices may not be willing to overturn court precedent that’s more than a century old, and the case could result in an embarrassing defeat.

“It’s a remarkably weak case, not only because the Supreme Court answered this question 128 years ago, but because Congress wrote that answer into federal law in both 1940 and 1952,” said Steve Vladeck, CNN Supreme Court analyst and professor at Georgetown University Law Center.

“That means that Sauer has to persuade the justices not only that they’ve been wrong for more than 125 years, but that Congress didn’t do what it clearly did twice – by deciding as a matter of statute to adopt the rule the court read into the 14th Amendment. That’s quite an uphill climb even before we get to the implications.”

Sauer’s argument will focus largely on the 14th Amendment, which states that “all persons born … in the United States, and subject to the jurisdiction thereof, are citizens of the United States.”

According to a senior Justice Department official, Sauer’s argument will try to get the justices to agree to his definition of what it means to be “subject to the jurisdiction thereof.”

“You are talking about people who have the requisite relationship, are part of our political community and have something akin to the sort of complete and thorough allegiance that US citizens have,” the official said.

Sauer will argue that anyone who has entered the country illegally or overstayed their visa would not meet this requirement. He will also argue that the children of people who have traveled to the US as tourists do not qualify.

“They also don’t have the requisite relationship of allegiance to the United States. They’re not subject to jurisdiction … and therefore, their children are not citizens,” the person added.

Related article Rodica Cojocaru / 500px/Getty Images Immigration advocates appeal to a higher power to sway the high court on birthright citizenship 6 min read

It is unclear whether a loss on the biggest case of the year would hurt Sauer’s standing with the president, but allies are already providing him some cover by pre-emptively shifting blame to the justices who will decide the case and not the man who will argue it.

“If the justices follow the law … this is an easy decision. If the justices embrace politics, then it’s a messy decision,” Davis said.

Sauer’s path to solicitor

Sauer is no stranger to the high court. He clerked for the late Justice Antonin Scalia after graduating from Harvard Law School. He worked as a prosecutor and then at various boutique law firms before serving as solicitor general of Missouri for six years.

Trump hired Sauer, along with two other attorneys, once his challenge to criminal charges filed against him by special counsel Jack Smith reached the Supreme Court in 2024. That historic argument was Sauer’s second time arguing before the justices. His first was as Missouri solicitor general when he successfully defended the state’s lethal injection protocol.

Sauer helped save Trump from facing criminal trial by convincing a 6-3 court that presidents have absolutely immunity for actions taken within their core duties.

“People mocked John Sauer when he raised presidential immunity. They’re not laughing anymore,” Davis said.

In Trump legal circles, Sauer has also distinguished himself for being well-liked as a person.

Related article UNSPECIFIED – UNDATED: In this handout image provided by The White House on May 26, 2009, Judge Sonia Sotomayor is seen with her mother Celina Sotomayor and father Juan Luis Sotomayor in this undated family photograph. If approved by the U.S. Senate, Sotomayor will be the first Hispanic and the third woman ever to serve on the Supreme Court. Sotomayor currently sits on the United States Court of Appeals for the Second Circuit, based in New York. (Photo by The White House via Getty Images) The White House/Getty Images Supreme Court justices will consider the future of birthright citizenship. Here’s how their families came to America 11 min read

“He has impeccable legal credentials, but he has Midwestern sensibilities and modesty,” Davis said.

A big part of Sauer’s success has been teeing up litigation in a manner most likely to be met with a sympathetic ear – even if he didn’t win every case. But with birthright citizenship, the court forced him to bring the issue back after it agreed to limit nationwide injunctions.

“He’s been able to play a bunch of home games with the court to this point; even though the government was the nominal petitioner here, this is really an away game – where the party that really wanted the court to decide the merits was the court itself,” Vladeck said.

But even with the odds stacked against him, Sauer’s record shows you cannot count him out.

“You can never say never with this court, especially when it comes to President Trump,” Vladeck added.

Donald Trump Supreme Court

See all topics

Facebook Tweet Email Link Threads

Link Copied!