While Trump has enjoyed a remarkably successful track record so far before the high court during his second term, particularly on the shadow docket, many experts say there is widespread uncertainty over how the Supreme Court will rule on the momentous tariff case.

“It’s very uncertain given the makeup of the court,” Gregory Shaffer, a Georgetown Law professor who co-wrote an amicus briefing backing the lower court rulings against Trump, told The Post.

“It could be 50-50,” he added. “There are some justices, such as Justice [Neil] Gorsuch, who have earlier expressed concerns about Congress delegating its powers to the president.”

Since February, Trump has signed a raft of executive orders slapping tariffs on various countries.

At issue is Trump’s use of the International Emergency Economic Powers Act (IEEPA), which has been used to impose two key types of tariffs: “trafficking” duties aimed at countries for fentanyl flowing into the US, and “worldwide” or “reciprocal” tariffs imposing blanket levies due to concerns about the trade deficit.

That’s the bulk of Trump’s tariff regime.

The IEEPA, which was passed in 1977, gives the president emergency powers to “investigate, block during the pendency of an investigation, regulate, direct and compel, nullify, void, prevent or prohibit … importation or exportation” of international commerce.

Crucially, the IEEPA makes no mention of the word “tariff,” and no president has ever wielded the law the way Trump has to impose sweeping worldwide tariffs in the nearly 50 years it’s been on the books.

That is one of the key reasons why petitioners argue Trump can’t use IEEPA for his tariff blitz, and they hope that will appeal to the conservative majority’s originalist philosophy, which focuses on text and its intended meaning.

While no chief executive has ever used the IEEPA to impose tariffs, President Richard Nixon notably used the precursor law, the Trading with the Enemy Act of 1917, to implement a 10% duty on imports into the US.

The Supreme Court will hear a consolidated case based on challenges — one from a family-owned firm that make toys and a second from a wine importer and seller of women’s cycling apparel — that are both arguing the IEEPA doesn’t give the president power to impose tariffs.

The lower courts have ruled against the president.

“Congress doesn’t need to use the word ‘tariff’ to delegate tariff power,” Chad Squitieri, a professor at Catholic University’s Columbus School of Law, who backs Trump’s perspective, countered. “The ordinary meaning of the phrase ‘regulate … importation’ includes tariff power.”

The lower courts have ruled against the president.

“Like how the ordinary meaning of a hypothetical statute mentioning ‘professional sports’ would be read to cover ‘baseball,’ the ordinary meaning of the phrase ‘regulate … importation’ is best read to include the power to impose tariffs.”

In many instances, the Supreme Court has shown deference to the presidency for national security issues, which could benefit Trump.

“I think they [the originalists] nod off in different directions on that,” Paul Stephan, a law professor at the University of Virginia School of Law, told The Post.

“That claim that runs through many of the briefs, particularly those supporting the government,” added Stephan, who also filed an amicus brief against Trump’s tariff actions and believes the Supreme Court may rule against the president. “I’m not sure that it gets you over the goal line.”

Another key legal principle that could come up during oral arguments is Article I of the Constitution, which bestows Congress with the power to “lay and collect Taxes, Duties, Imposts and Excises.”

“The Roberts Court has held that where a statute is ambiguous and is subject to more than one reading, the court will apply the reading which will not raise a fundamental constitutional question,” Shaffer explained.

“If it applies that doctrine, the constitutional avoidance doctrine, then it will decide that ‘regulate’ doesn’t include setting tariffs.”