Friday evening, a federal court blocked much of the funds President Trump hoped to use to build an illegal wall along the Mexican border, and strongly implied that an even larger tranche of funding is illegal as well.

Under the terms of Judge Haywood Gilliam’s order in Sierra Club v. Trump, the Trump administration may not redirect certain Defense Department funds “to construct a border barrier in the areas Defendants have identified as Yuma Sector Project 1 and El Paso Sector Project 1.” By its explicit terms, Judge Gilliam’s order does not apply to other sections of the Mexican border, nor does it apply to other potential funding sources. Nevertheless, its reasoning would severely undercut Trump’s ability to build his wall.

The Trump administration asked Congress to provide $5.7 billion in funding for a wall along the Mexican border, but Congress largely rejected that request (although it did approve less than $1.4 billion for “the construction of pedestrian fencing, of a specified type, in a specified sector” of the border).

Trump responded to this rejection by shutting down much of the government for more than a month in late 2018 and early 2019. He then announced that he would declare an emergency and attempt to transfer funding from existing appropriations to wall construction. In total, the Trump administration claims that it “identified up to $8.1 billion that will be available to build the border wall once a national emergency is declared.”

The two largest sources of these funds include $2.5 billion under a statute permitting Defense Department funds to be reallocated to support anti-drug activities, and $3.6 billion reallocated from the Defense Department’s military construction projects.

Because the Trump administration has not yet identified which military construction projects will be canceled or delayed to accommodate Trump’s wall, Judge Gilliam concludes that it would be premature to enjoin Trump’s effort to transfer those funds. Nevertheless, his opinion in Sierra Club strongly suggests that Trump may not lawfully use military construction funds to build his wall.

Though a federal statute does sometimes permit military construction funds to be reallocated, Gilliam explains, these funds may only be shifted when applied to other “military construction projects,” and Trump’s wall does not qualify. The statute defines such a project as “any construction, development, conversion, or extension of any kind
carried out with respect to a military installation . . . or any acquisition of land or construction of a defense access road.” And Trump’s wall simply isn’t a “military installation.”

The most significant part of Gilliam’s opinion, however, is his analysis of whether Trump can divert Defense appropriations to an anti-drug fund, and then claim that the wall will prevent illegal drugs from entering the United States.

Among other things, Gilliam notes, the administration can only invoke this power when it does so because of “unforeseen military requirements,” but there’s nothing about the so-called border emergency that Trump cites to justify his wall that is “unforeseen.” As a presidential candidate, Trump constantly called for a wall along the Mexican border. Fully one year before Trump announced his plans to divert funds to build his wall, the president called for a border wall in a letter accompanying his proposed 2019 budget. The budget itself claims that a wall “is critical to combating the scourge of drug addiction that leads to thousands of unnecessary deaths.”

Trump, in other words, did not reallocate funds because of some unforeseen military necessity that requires him to bypass the ordinary congressional appropriations process. Rather, Trump announced that he saw the need for a border wall many times over the course of the last three years. He personally requested money to build that wall from Congress, and Congress quite explicitly rejected that request.

The supposed border emergency was entirely foreseen by Trump. Congress just disagrees with Trump about what to do about it. As Judge Gilliam explains, the law does not permit Trump to divert Defense funding under these circumstances.

Of course, the fact that Trump’s efforts to build his wall are largely illegal does not mean that the wall won’t ultimately get built. It is likely that Judge Gilliam’s decision will ultimately be considered by the Supreme Court, and this Supreme Court is quite willing to let Trump violate the law — even when Trump’s own words undercut his legal arguments. Just look at what happened in the Muslim ban case.

Nevertheless, Gilliam’s decision is significant because, at the very least, it delays Trump’s plans to build the wall. Each day that passes brings us closer to the day that Trump leaves office. And if lower federal courts can keep Trump from building his wall until that day comes, the Supreme Court’s views on whether Trump can break the law could very well become moot.