When the US Supreme Court's nine justices gather in their ceremonial chamber in early November, topping the docket will be Donald Trump's use of emergency powers to impose blanket tariffs on trading partners.
The case marks the first time the court will squarely tackle the legality of the president's sprawling second-term agenda. The decision will affect not just global trade but may shape the American government for decades.
The Supreme Court is in the midst of what could be one of the most consequential periods in its history. Learning Resources vs Trump is among many cases that could rewrite everything from presidential power to US citizenship.
Leah Litman, professor at the University of Michigan Law School, said: "Even though the court didn't explicitly address the merits of various Trump policies over the last few months, it has allowed the president to do very sweeping things," including deporting people to third countries.
The full hearing on the tariffs case is "significant because we will have some insight into what they are thinking", Litman added.
Trump's critics believe the court has a constitutional duty to be a bulwark against his autocratic impulses: a check on what he claims is his right to bend institutions to his will, persecute political opponents and bypass Congress. More than 135 legal challenges to Trump's actions are moving through the courts.
If the top court allows Trump free rein, it risks "weakening and maybe destroying the US democratic republic and its constitutional system", said Barbara Perry, Supreme Court and presidency scholar at the University of Virginia.
But the president's supporters have high hopes that the court's 6-3 conservative majority, which includes three Trump appointees, will endorse his far-reaching project to remake America.
Several justices openly subscribe to a doctrine known as "unitary executive theory" which grants presidents broad authority, but it is not clear they constitute a majority on the specific issues at stake.
Here are some of the most important cases:
The Supreme Court fast-tracked the tariff case after lower courts found many of the levies to be unlawful.
The US Court of International Trade in May ruled Trump did not have the authority to use emergency economic powers legislation to impose blanket tariffs without Congress's consent. A US appeals court agreed.
"This case addresses the validity of the administration's most significant economic and foreign-policy initiative," the government wrote in a Supreme Court filing.
The top court would have to "wrestle" with broad questions including the use of emergency powers as well as the government's argument that tariffs are "wrapped up" with the president's foreign affairs powers, said Kathleen Claussen, a professor at Georgetown Law.
She noted conservative justices Neil Gorsuch and Brett Kavanaugh have suggested there could be "special treatment for foreign affairs under various principles and doctrines".
But while this is a critical case for businesses hit by the levies, if the top court rules against Trump, "I still don't see that as being a huge impediment to what he's trying to achieve," Claussen said, given other statutory options to impose tariffs.
A fight has broken out over Trump's authority to control independent agencies, centred on his attempt to fire the last Democratic commissioner at the top US antitrust regulator.
A trial judge ruled Rebecca Slaughter must be reinstated to the Federal Trade Commission while she challenges her dismissal, and a US appeals court last week held the decision must be enforced.
But the top court on Monday put this ruling on hold while it considers the broader issue. "I intend to see this case through to the end," Slaughter said on Monday.
The case hinges on a 1935 Supreme Court decision, Humphrey's Executor vs US, that upheld a law prohibiting the removal of FTC commissioners unless it was for cause.
The ruling is newly relevant as Trump seeks to remove Federal Reserve governor Lisa Cook -- a move she is challenging in court.
Richard Pierce, professor at the George Washington University Law School, said the justices "have already sent the message" in other "contexts [where] statutory limits on the president's power to remove someone are absolutely null and void".
He referred to their decision in May to block lower court orders halting Trump's removal of members of the National Labor Relations Board and the Merit Systems Protection Board. However, the order signalled Fed officials may be subject to stronger protections.
"The whole concept of independent agencies is gone," Pierce added.
Trump has used the Alien Enemies Act of 1798 to accelerate deportations. The wartime law, invoked via executive order, was last used in the second world war to intern non-US citizens of Italian, German and Japanese descent.
A US appeals court last week rejected Trump's use of the statute, finding "no invasion or predatory incursion" to justify it.
The case stems from individuals who were detained for being alleged members of a Venezuelan gang -- which they dispute. They also allege they were not given the chance to challenge their detention.
There is little Supreme Court precedent linked to the 1798 law. But in a narrower ruling earlier this year, the top court wrote: "Although judicial review under the AEA is limited, we have held that an individual subject to detention and removal under that statute is entitled to 'judicial review'."
Trump has deployed troops across US cities in response to what he says are public safety emergencies, while seeking to crack down on "sanctuary cities" -- jurisdictions that limit co-operation with federal immigration authorities.
He has sent in the National Guard and taken control of the local police department in Washington, and threatened to do the same in Chicago.
He also overrode California state officials and placed the California National Guard under federal control in June to quash protests against his administration's immigration crackdown.
A district judge last week ruled this violated the Posse Comitatus Act, which bars the US military from enforcing domestic law, but a US appeals court has put this decision on hold as it considers the government's appeal.
The case may also end up before the Supreme Court -- although there are few legal interpretations of the act, said Aziz Huq, professor at the University of Chicago Law School.
"The statutory framework is a very complicated one . . . that makes it more easy than not for the court do what it wants with the ultimate outcome," he said.
Among more than 200 executive orders Trump has issued, one of the most controversial curbs birthright citizenship, which automatically grants US nationality to all children born in the country, including those of undocumented immigrants.
Critics say the order conflicts with the US constitution's Fourteenth Amendment. The president argues the amendment was not meant to "extend citizenship universally".
The issue has been to the Supreme Court once, after lower courts blocked the nationwide application of Trump's order. But the justices sidestepped the core question in June and instead ruled on a technical issue, voting 6-3 to limit judges' power to make rulings with national scope.
A flurry of nationwide class-action lawsuits still challenge the president's authority -- and at least one judge has certified a class covering all individuals whose citizenship is denied by the order and blocked its enforcement.
The administration has filed a notice of appeal, and some legal experts argue it may be hard for the government to win. Some conservative justices have joined the liberals in expressing scepticism.