In 1981, Egyptian President Anwar Sadat was assassinated, and a state of emergency was imposed. It was finally lifted in June 2012, after President-turned-Dictator Hosni Mubarak was finally overthrown. In 1933, Adolf Hitler and the Nazi party seized on the Reichstag Fire (or perhaps staged it themselves), requested emergency powers, then used them to do things like ban political parties. By 1934, Hitler had become the Fuhrer.

Which brings me to Donald Trump and his new obsession with emergency powers—which essentially remove constraints on the presidency—with the idea being that the executive branch should have maximum flexibility in a crisis.

2. POTUS, encouraged by friends on right, increasingly sees a nat'l emergency declaration as a way to rattle empowered Dems and show his core voters he's going to the brink for wall — Robert Costa (@costareports) January 8, 2019

The constitution does not explicitly give the president emergency powers, but legal scholars believe that it is implied. The U.S. Supreme Court upheld Franklin Delano Roosevelt’s emergency power declaration in Korematsu v. United States, asserting that he did have the legal right to declare an emergency and throw over 100,000 Japanese-Americans in concentration camps during World War II. The Supreme Court has also ruled against presidential emergency powers, like when Harry Truman tried to nationalize steel mills in 1952 after a labor strike, asserting that he could not fight the Korean War without those resources. The law is far from settled on this topic, and the proof is in instances like when Abraham Lincoln ignored a Federal District Court ruling striking down his emergency powers after he suspended habeas corpus.

This article in The Atlantic does a good job providing some specifics on what powers Trump can actually give himself:

The moment the president declares a “national emergency”—a decision that is entirely within his discretion—more than 100 special provisions become available to him. While many of these tee up reasonable responses to genuine emergencies, some appear dangerously suited to a leader bent on amassing or retaining power. For instance, the president can, with the flick of his pen, activate laws allowing him to shut down many kinds of electronic communications inside the United States or freeze Americans’ bank accounts. Other powers are available even without a declaration of emergency, including laws that allow the president to deploy troops inside the country to subdue domestic unrest.

This is all about the wall, which is under the legislature’s purview. Congress controls the purse strings for government, which means that typically they would need to appropriate money for Trump’s border wall. However, there are a couple laws on the books that may allow Trump to circumvent congress if he were to declare emergency powers.

33 U.S. Code § 2293 enables the secretary of the Army to stop Army civil works projects, and direct their energy towards building “authorized civil works, military construction and civil defense projects that are essential to the national defense.” 10 U.S. Code § 2808 gives the Secretary of Defense the power to begin military construction projects that are “not otherwise authorized by law that are necessary to support such use of the armed forces.”

These are Trump’s most legal paths to building his wall, but they are certain to involve a court battle. The problem that legal challenges to Trump will encounter is that whether there is an actual emergency underlying an emergency powers declaration likely would not factor into the case, because it would require judges to replace the president’s thinking with their own. While this sounds nonsensical—essentially conceding that the president can say anything he wants and it becomes reality—the fact of the matter is that The National Emergencies Act passed by Congress gives the president this kind of power. The New York Times has more on this unintended consequence:

When passing many emergency-powers laws, Congress attached a procedure that would let lawmakers override any particular invocation of that authority. The National Emergencies Act, for example, permitted Congress to rescind an emergency if both the House and the Senate voted for a resolution rejecting the president’s determination that one existed.

But in 1983, the Supreme Court struck down such legislative vetoes. The justices ruled that for a congressional act to have legal effect, it must be presented to the president for signature or veto. Because it takes two-thirds of both chambers to override a veto, the ruling significantly eroded the check and balance against abuse that lawmakers had intended to be part of their delegation of standby emergency powers to presidents.

This is legitimately scary. While the courts have proven they can rein in some of the president’s emergency powers, Congress is the entity tasked with immediate checks on executive power, and not only do we have a Republican Senate unwilling to take on Trump, but there is a serious question as to whether any Congress would be able to do anything to stop Trump without a two-thirds majority. While the United States has far more guardrails in place than other countries like Egypt who have fallen into a perpetual state of emergency, the legal history of presidential emergency powers is murky, and as Abraham Lincoln proved with his suspension of habeas corpus, the president can ignore a court ruling and get away with it.

While we are still some distance from anything resembling a true dictatorship, we are far closer than any of us had imagined in 2016. Trump has the legal authority to declare a national emergency, and precedent indicates that he doesn’t even need to justify the facts of the supposed emergency. Hosni Mubarak used emergency powers to turn his presidency into a dictatorship, and given Trump’s obsession with autocrats, we would be naïve to think that he hasn’t considered that aspect of this move. The history of emergency powers across the globe demonstrates that there is a real danger in being unable to take this power away from those who award it to themselves, and whatever happens tonight with Trump’s national address, if he gives himself the power to shed restrictions on the executive, the survival of our republic depends on taking it back.

Jacob Weindling is a staff writer for Paste politics. Follow him on Twitter at @Jakeweindling.