The Supreme Court will hear oral arguments Wednesday in Trump v. Hawaii, the long-awaited challenge to President Donald Trump’s travel ban targeting eight countries, six of which are Muslim-majority. It marks a watershed moment for Trump’s presidency: the first time that one of his signature policies will come under the justices’ scrutiny.

Technically, the Justice Department has been arguing cases before the high court on Trump’s behalf for more than a year now. But this one is wholly Trumpian. In 2015, Trump campaigned on a “total and complete shutdown” of Muslim travelers into the United States. He later amended the policy to one of “extreme vetting” to prevent would-be terrorists from entering the country. In practice, the travel ban led to chaos at U.S. airports, nationwide protests, and widespread legal challenges.

Every president’s actions are tested by the court and, occasionally, the executive branch loses. An evenly split court dealt Barack Obama a major blow on immigration in 2016 by blocking his order to protect millions of undocumented immigrants from immigration and allowed them to work legally, and it came within a hair’s breadth of striking down the Affordable Care Act four years earlier. The justices spent years trying to impose some kind of constitutional order on George W. Bush’s Guantanamo Bay detention program. And the court’s ruling in 1997 that Bill Clinton wasn’t immune from Paula Jones’s sexual harassment lawsuit set in motion a chain of events that culminated in his impeachment.

Trump likely will face adverse decisions at some point, too. The question is whether he will respond as his predecessors did: by humbly (or begrudgingly) accepting the court’s will.

Trump has been openly hostile to judicial constraints to an unprecedented degree. Under his watch, immigration officials have defied multiple court orders halting an earlier version of the travel ban, which applied to seven Muslim-majority countries. Before taking office, he launched racist attacks on judges who ruled against him, as president has angrily denounced “so-called judges” who have thwarted him. Neil Gorsuch, after Trump nominated him to the Supreme Court last year, criticized the outbursts as “disheartening” and “demoralizing,” which reportedly prompted Trump to briefly consider withdrawing his nomination.