The president, before his trip to Texas on Thursday. Photo: Mark Wilson/Getty Images

In a Thursday evening interview on Hannity, in front of a strongman’s backdrop of armored vehicles, border patrol agents, and a bale of seized marijuana, President Trump refused to give a timeline on his decision to declare a national emergency to build a southern border wall. He did, however, provide an interesting lesson in basic human technology, after pointing out the wheels on a truck: “The wheel is older than the wall, you know that? There are some things that work. You know what? A wheel works and a wall works. Nothing like a wall.”

Though the interview did not shed any light on when a national emergency could be announced, reporting from Thursday did clarify how it might happen. According to the Washington Post, the Trump administration may co-opt a disaster spending bill in the Army Corps of Engineers budget. With the declaration of a national emergency, Trump could pivot $13.9 billion allocated for civil projects toward the wall, expecting the funds to cover around 315 miles of the barrier (there is already some kind of barrier along 650 miles of the 2,000-mile border). The administration also reportedly asked if the Army Corps could have contracts ready to start building within 45 days.

The plan could be very unpopular in the three most populous states in the nation. Aside from the constitutional crisis inherent in the fabrication of a national emergency, it would divert disaster funding from flood management projects along the Texas coastline hit by Hurricane Harvey, hurricane rebuilding efforts in Florida and Puerto Rico, and a litany of infrastructure projects in California. The administration would pull $2.4 billion slated for the Golden State, including wildfire management, and flood protection around the Yuba River Basin and the Folsom Dam. In Puerto Rico, $2.5 billion would be withdrawn from reconstruction after Hurricane Maria, a storm — and subsequent man-made crisis caused by Trump administration mismanagement — that killed 3,507 Americans. Meanwhile, FEMA has suspended hundreds of disaster-relief contracts during the shutdown.

In some ways, it would be a perfect capsule of Trump’s domestic policy: diverting funds from actual disasters to fund a gesture of xenophobia that, judging from the current prototype, could be cut through with a saw. In the original Corps of Engineers budget, the $13.9 billion marked a crucial rebuilding opportunity in the quiet months of the wildfire and hurricane seasons, both of which are rapidly expanding as the planet marches toward the hothouse. And if the plan goes through, it could have swing-state ramifications in 2020: The president’s net approval in Florida is currently at 46 percent, a rating that isn’t likely to go up by siphoning emergency funding from the state.

If the president decides to reallocate the Corps of Engineers budget, Democrats are prepared with a countermove in the court and the House. Politico cites a 2014 suit in which House Republicans sued the Obama administration for directing the Health and Human Services Department to fund Obamacare subsidies for the poor, circumventing Congress. “The decisions were very strong in the House’s favor in that lawsuit,” Kerry W. Kircher, the lawyer in the 2014 lawsuit, told Politico. “The judge was very resolute that the executive does not get to spend money that Congress has not given it.”

According to NBC News, if the president decides to reallocate the Corps of Engineers budget, Democrats are prepared to submit legislation to block the move — though passing it in the Senate would be another matter. “It would be beyond appalling for the president to take money from places like Puerto Rico that have suffered enormous catastrophes, costing thousands of American citizens lives, in order to pay for Donald Trump’s foolish, offensive, and hateful wall,” New York representative Nydia Velázquez said.