During his campaign for president, Donald Trump said he’d only be a dictator on “Day One,” when he would “close the border” to nearly all immigrants. True to his word, when Trump entered office, he signed executive orders that sought to rewrite the Constitution and explicitly override the law to restrict immigration.

But those executive orders didn’t expire on Day Two. The president is still exercising dictatorial powers on immigration, and it isn’t yet clear that anyone will stop him. Several court decisions have sought to rein him in, and the Supreme Court should also intervene, if necessary. Whatever one thinks of immigration, any limits must be imposed lawfully.

Trump’s theory of presidential control over immigration goes well beyond his predecessors’. In an executive proclamation issued within hours of being inaugurated, Trump asserted that he has total power to shut down virtually all legal immigration and ignore laws that protect immigrants from wrongful detention and deportation.

The president indicated that he can unilaterally suspend Congress’ immigration laws because they are “ineffective,” even though the Constitution gives Congress – not the president – the authority to make laws.

Actual invasions trigger some extraordinary powers under the Constitution. The government – including state governments – can wage war, and the federal government can detain even U.S. citizens without charge or trial. That means Trump’s power grab over immigration policy could be one of the most dangerous in American history.

Media reports indicate that Trump may also be about to use the “invasion” theory to invoke the Alien Enemies Act of 1798 as a tool for deportation, initially focused on members of a Venezuelan drug gang. If courts uphold this use of the act in this instance, the administration could potentially detain and deport even legal immigrants with little or no due process. However, the act can only be used in the event of a declared war, or an “invasion” or “predatory incursion” perpetrated by a “foreign nation or government.” The U.S. is not at war, illegal migration and drug smuggling do not qualify as an “invasion,” and illegal migrants and drug smugglers are pretty obviously not nations or governments.

Trump is also claiming that he can deny “birthright citizenship” to children of undocumented immigrants and those in the U.S. on temporary visas. That means people who under the Constitution are natural-born Americans could soon be deported. Multiple federal courts have for now blocked implementation of this policy, which the president wanted to apply to those born 30 days after his executive order or later. But the president has appealed, and also asked the Supreme Court to narrow the scope of the lower-court rulings against the order, thereby allowing it to partially go into effect.

The 14th Amendment, ratified in 1868, grants birthright citizenship to anyone born in the United States “and subject to the jurisdiction thereof.” The longtime legal consensus is that this includes children of undocumented immigrants, a group that Trump has disparaged as “anchor babies” used by their parents to try to remain in this country. Foreign diplomats are the only group in the United States today whose children born on U.S. soil are excluded from birthright citizenship, because diplomats have diplomatic immunity and hence are not subject to U.S. law.

If Trump’s absurd claims that children of noncitizens without permanent status are not “subject to U.S. jurisdiction,” that would mean that unauthorized immigrants and temporary residents cannot be prosecuted for crimes they commit here. Consider the irony.

Trump is also busy trying to negate the 10th Amendment, which protects the independence of state governments. He is threatening criminal prosecution of state and local officers who refuse to take orders from his deportation agents, and he is already illegally withholding federal grants from some cities to unconstitutionally coerce them into cooperation.

This coercion is clearly not allowed. During Trump’s first term, numerous federal court decisions – some handed down by conservative judges – rejected his attempts to pressure sanctuary cities and states to help out with deportations by withholding federal funds.

But the Trump train of immigration policy lawlessness stretches even further. Cases are pending against his administration for suspending legal entries for refugees; for withholding of already appropriated money for refugees; for allowing agents to deport some people without due process; for terminating asylum; and for holding migrants in a detention facility in Guantanamo Bay, Cuba, without due process.

Trump is attacking the rule of law so quickly and from so many directions that courts may not be able to stop all the abuses. Moreover, Trump’s vice president, JD Vance, and his homeland security advisor, Stephen Miller, have suggested he is not required to follow court orders when courts rule against him.

There is reason to fear the White House is already refusing to adhere to court rulings. A federal judge already found on Feb. 10 that the administration is at least partially defying a court order on non-immigration issues. Similarly, another federal judge issued a second court order requiring compliance in another case – after the administration apparently failed to comply with his first one. Trump himself wrote last month, “He who saves his Country does not violate any Law.” If Trump is permitted to continue defying the courts, we will have a grave constitutional crisis.

Trump isn’t the first president to test the limits of executive power on immigration. But such sweeping claims to unchecked authority that openly defy the Constitution, federal law and court decisions are unique in modern times.

Whether Trump prevails here will decide not just the future of immigration, but the future of America. The courts must stand against such violations because it’s not just immigration that’s at stake; it’s our system of rule of law