AN “INVASION”. That’s how Donald Trump describes migration across America’s southern border. “For American citizens, January 20th 2025 is Liberation Day,” he said in his inaugural address. The notion that America is being invaded is the defining theme of ten executive orders on immigration and border enforcement he signed on his first day in office. This is despite the fact that encounters at the border are the lowest they have been in four years. The orders fall into three categories: the rescission of Joe Biden’s policies and reinstatement of Mr Trump’s first-term plans; flashy things that sound tough; and extreme measures that range from probably illegal to flagrantly unconstitutional.

In the first group Mr Trump issued a sweeping order that aims to increase detention, coerce countries to take back their citizens, encourage local police to help with immigration enforcement and punish sanctuary cities, among other things. He resurrected Remain in Mexico, a policy he introduced in 2019 that forced migrants to wait on the other side of the border while their asylum claims were adjudicated.

He also shut down CBP One, an app set up by the Biden administration that helped migrants schedule appointments to apply for asylum. Migrants already in the queue found their meetings abruptly cancelled after Mr Trump took office. During his first term, the number of refugees relocated to America plummeted. This time he suspended all refugee resettlement for at least three months. Another order increases vetting for migrants and directs agencies to identify whether there are countries from which travel should be prohibited, perhaps a prelude to a ban like the one Mr Trump imposed on arrivals from mostly Muslim-majority countries in 2017.

Some orders sound harsh but may not change much. One that demands physical border barriers, detention and deportation is “just calling for enforcing laws that are already on the books”, says Julia Gelatt of the Migration Policy Institute, a think-tank. Additionally, Mr Trump declared a national emergency at the southern border, which allows the defence secretary to send troops to help secure the frontier with Mexico. George W. Bush and Barack Obama did something similar. Federal law limits soldiers’ roles in domestic affairs to non-law-enforcement activities such as transport and logistical support, rather than actually arresting migrants. The national emergency also unlocks funds from the Department of Defence for the fortification of the border wall, a move the president made in 2019, too.

That leaves the most extreme orders. One aims to end birthright citizenship, which is enshrined in the 14th Amendment . The new president kickstarted the lengthy process of classifying drug cartels as foreign terrorist organisations and directed top officials to prepare for the possibility that he will invoke the Alien Enemies Act, the only piece of the Alien and Sedition Acts, passed in 1798 when America was feuding with France, that was not repealed or allowed to lapse. It permits the president to summarily detain and deport citizens of countries at war with America. Yet America is not at war, and drug gangs are not sovereign states, even if they do control some territory.

This is where Mr Trump’s talk of an “invasion” becomes more than rhetorical bombast. Framing the cartels as terrorists invading America is meant to legitimise his use of the law. And because America is being invaded, Mr Trump argues, he can block anyone from crossing the border. The courts may not see it that way.■

Stay on top of American politics with The US in brief, our daily newsletter with fast analysis of the most important political news, and Checks and Balance, a weekly note from our Lexington columnist that examines the state of American democracy and the issues that matter to voters.