[Read: What the president could do if he declares a state of emergency]

National emergencies, as Americans know them today, are an artifact of another era of expansive executive power. As allegations from the Watergate scandal were closing in on President Richard Nixon, he began declaring national emergencies in response to everything from a postal strike to a trade imbalance, says Kim Lane Scheppele, a professor at the Woodrow Wilson School of Public and International Affairs at Princeton University. Congress sought to regulate this presidential power, which had also been used liberally by prior presidents, with its 1976 National Emergencies Act.

But as Elizabeth Goitein recently wrote in The Atlantic, this law still left presidents with extensive power and little accountability. So-called emergencies have been left in place “for years on end” without congressional oversight; the president is required to do little to justify any action he takes. Trump’s possible use of the national-emergency mechanism might be novel, but “the national-emergency system has been ripe for abuse for a long time, and has been gently misused for decades,” Goitein told me. “The conversation is long overdue.”

In other words: The most remarkable thing about Trump’s national-emergency solution to the border-wall impasse is not that he is breaking laws, but that he’s working within them. “It’s the first time that he’s actually done something that looks like he talked to a lawyer first,” Scheppele said. “Trump is actually, weirdly, coloring within the lines Congress drew. And that’s an improvement over what he usually does.”

Democrats will likely sue Trump in court if he does in fact declare a national emergency. Legal scholars have debated who would win in that scenario, but “the strategy [Trump is reportedly] proposing,” of using a national emergency to reallocate previously apportioned funds, “is pretty legally sophisticated,” Scheppele said. Under the statute, the president has latitude to determine what a national emergency is, according to a new report from the Congressional Research Service, and courts have typically deferred to presidential judgment in this area.

[Read: FBI agents say the shutdown is a threat to national security]

In many ways, the reason this situation has escalated to this point is because of Congress’s inability to govern. Over time, lawmakers have increasingly relied on the executive branch—to which it has granted expansive power—to make policy. This is arguably both a cause and an effect of partisan tribalization, which also led to this deadlock: In recent weeks, Republicans have intentionally blocked efforts to reopen the government. In the past decade, despite many tries, legislators haven’t been able to pass comprehensive immigration reform.

In the absence of a functioning legislature, Democrats have become increasingly reliant on courts to fight Trump on everything from the ban on immigrants and refugees from predominantly Muslim countries to the proposed removal of transgender military service members. Their success has been mixed. “Everybody wants the law to provide the answer. But the answer here is a political answer,” Scheppele said. “The judges are not that likely to say no here.”