President Donald Trump’s hastily called “press conference” on Thursday afternoon — in which neither he nor press secretary Sarah Sanders took questions — was less a press conference, in the traditional sense, than a way for Trump to signal-boost a politically helpful message.

And that message, delivered by Brandon Judd, Art Del Cueto, and Hector Garza of the National Border Patrol Council (the union representing Border Patrol agents) was this: Border Patrol agents are willing to keep the government shut down for as long as it takes to get the money Trump wants for his border wall — even if that means they have to continue working without pay.

Generally, a public sector union would hardly be expected to make a public appearance urging Congress not to pass a bill that would start paying their salaries again. But Judd and the other leaders of the National Border Patrol Council aren’t your typical public sector union — and have now become, by all appearances, closer allies to Trump than some of his appointed officials.

The Border Patrol union sees hawkish immigration policy as the key to employee morale

Generally, unions are expected to advocate for one of two agendas: the immediate, bread-and-butter needs of their membership (pay, benefits, time off, discipline) or the health of unions themselves (for card check, against right-to-work laws, etc.). Indeed, the current wave of anti-union pushback in conservative courts (including the 2018 Supreme Court case Janus v. AFSCME) is grounded in the sense that unions are doing too much of the latter and not enough of the former.

They are not, generally, expected to advocate for or against particular policies that are their members’ jobs to implement.

But when it comes to law enforcement unions, that line often gets blurry. Unions are supposed to advocate for the safety of their members — so police unions often feel a mandate to oppose anything from restrictions on the use of deadly force to greater transparency around officer misconduct. More broadly, a suspicion that a policy may make officers less safe can be used to justify opposition to a lot of things — from ending stop and frisk to deprioritizing marijuana arrests to simply making comments about tensions between police and minority communities.

The federal immigration enforcement unions are law enforcement unions, and they’re far to the policy advocacy side of the scale. They’ve consistently advocated for a more hawkish immigration enforcement policy, one that allows (or even requires) agents to arrest and detain every unauthorized immigrant they find and reduces opportunities for people who come without papers to get legal status in the United States.

Instead of seeing immigration enforcement as just a matter of officer safety, crucially, they see it as a matter of officer morale.

The Department of Homeland Security consistently scores very badly on employee morale surveys, and the department has been plagued by management and organizational problems since its creation in 2002 (which is unsurprising given how hastily it was cobbled together). And the voice of that discontent has been the enforcement unions — who claim that the morale problem is really a policy problem.

In their telling, Border Patrol (and Immigration and Customs Enforcement) agents are driven by their mission — to enforce immigration law and catch lawbreakers. Anything that would appear to restrain that mission, such as limiting who they can and can’t arrest or having to care for large groups of unaccompanied children and families, isn’t just an inconvenience to them but an active insult to the reason they signed up for the job.

There’s definitely an element of truth to this, though it’s not clear how far it goes. We don’t know whether the average Border Patrol officer has the same policy preferences as union leadership, or whether the rank and file care more about bread-and-butter issues than about policy.

And right now, that difference could be acute. Border Patrol agents are being forced to work without pay while the government is shut down — as essential employees, they’re working without regard to the shutdown, but the paycheck that is supposed to arrive January 11 won’t come. They’ll probably be given back pay once the government reopens, but that’s no guarantee — and with no end to the shutdown in sight and key members of Congress saying it could go on for “months and months,” federal employees are generally getting worried.

It’s worth noting that National Border Patrol Council executives get paid salaries by the union. Judd made $40,000 in 2015, according to the anti-union Center for Union Facts, with “total compensation” of more than $140,000. The executives have something of a cushion; their members do not.

But there’s really no way to know whether the union represents its members or not. It’s accepted by the public that Judd, Del Cueto, and Garza speak for the officers on the ground. And those men support Trump, in shutdown and in health.

Trump trusts Judd and labor over his own political appointees

Judd and other NBPC officers became a mainstay of conservative media during the Obama administration, criticizing the past president’s immigration approach as an insult to his men. They frequently vented to Breitbart, and their podcast The Thin Green Line mixed quotidian union complaints (their uniforms’ unsuitability for the humidity of the Rio Grande Valley, the fact that border agents are often stuck patrolling remote sectors with few chances for transfer) with praise for then-candidate Donald Trump.

The NBPC endorsed Trump in March 2016, before he’d even won the Republican nomination for president. Trump bragged about their endorsement incessantly in the last six weeks of the campaign. He’s consistently treated Border Patrol agents as a key constituency, bragging endlessly about their bravery and complaining that the media doesn’t give them enough credit. And the union, for its part, was able to educate Trump when his ideas didn’t exactly mesh with what line agents wanted (an opaque concrete wall instead of a “see-through” bollard wall, for example), while encouraging him to hold the line against unauthorized immigration more generally.

Through all this, Trump has run hot and cold on the people he’s actually appointed to run his government. He loved his first homeland security secretary, John Kelly, so much, he promoted him to White House chief of staff — then soured on him, in part because Kelly admitted that the president’s rhetoric about a border wall outstripped what his government was actually asking for. He has yelled at Kelly’s successor Kirstjen Nielsen, and was apparently on the verge of firing her this fall for not being hawkish enough on immigration.

While Trump appears to have warmed up a bit toward Nielsen, reportedly telling people that she’s tougher than he thought, Nielsen wasn’t at his press appearance Thursday. Neither were any other DHS officials Trump has appointed. In fact, Customs and Border Protection Commissioner Kevin McAleenan was supposed to have a briefing of his own for press at 4:30 on Thursday — it got delayed, and then canceled, when the president called the last-minute “briefing” of his own.

At times, Judd has been there to back up Trump against Nielsen. At a tense White House meeting before Thanksgiving, for example, he reportedly teamed up with Trump to overrule both Nielsen and Defense Secretary James Mattis over an order that would authorize broader use of military force at the US-Mexico border. It’s remarkable that Judd was even at that meeting — and more remarkable still that he prevailed over Cabinet officials.

But it makes sense. Judd isn’t responsible for delivering anything to Trump except himself: a tough-talking, seen-it-all border agent who defends the administration’s agenda. Trump hasn’t soured on him yet because he hasn’t needed to do anything but back the president. And right now, that means defending the wall — and minimizing the effects of a missed paycheck.