On Sunday morning, El Paso congressman and Democratic Senate candidate Beto O’Rourke led hundreds of protesters on a march to the new tent encampment for immigrant children—some recently separated from their parents—in the border city of Tornillo. The weather was sunny and warm. The Father’s Day crowd included smiling families. And the mood was spirited, with demonstrators holding signs with messages like “Fight ignorance, not immigrants” while chanting, “Ho, ho, hey, hey, don’t take those kids away!”

O’Rourke had publicized the event less than 24 hours earlier, and the turnout was impressive—“an amazing success,” O’Rourke would say later—with protesters arriving to walk with him and a group of other politicians that included Democratic gubernatorial candidate Lupe Valdez; El Paso congressional candidate Veronica Escobar; and Massachusetts representative Joe Kennedy III. But O’Rourke was also frustrated. His office had been struggling to get answers on exactly how the Trump administration’s family-separation policy was functioning. He’d asked to meet immigrant children inside the detention center and had been told he’d have to wait. He was getting ready to introduce legislation to end family separation, but he faced an almost impossibly uphill battle in a Republican-led Congress. (To say nothing of getting a signature from President Trump.) Like other lawmakers around the country who have tried to gain entry to immigrant detention centers with varying success, his congressional powers mattered less than his public platform and his social media accounts. (His March to Tornillo live stream has so far attracted almost 700,000 views.)

Last night we spoke with O’Rourke about the march, the impact of family separation, and the prospects for legislation to end it.

Texas Monthly: What was your goal with yesterday’s march?

Beto O’Rourke: We found out Thursday evening that there was a new children’s detention center going up in Tornillo and started calling HHS and CBP and trying to get details, and we really were having a hard time doing that. I was in Houston, and our former county judge who will very likely be our next representative in Congress, Veronica Escobar, reached out to me and just said, “Hey, I really think we all need to be there, even if we can’t go in. Even if we don’t know what all the plans are for this facility, we do know that there are kids there now.” We sent the notice out less than 24 hours before the actual event, and by any measure it was just an amazing success.

TM: Did you try to get access to the facility in Tornillo? As a member of Congress, are you even allowed to go into facilities at this point?

BO: It’s unclear. So, what we were told was we could get a briefing in the facility but not actually see any of the children in the facility. And if we wanted to do that, we needed to give two weeks’ notice, which I’ve asked my staff to do. But that puts us at the beginning of July. When we last checked, yesterday, there were 98 kids there. Today there are over 200 kids there, and the plans, or at least the plans that they are discussing—we don’t know if they’re committed to them yet—are to expand the capacity to 4,000.

Joe Kennedy went in, but he could not see the children. In fact, when he was there, they said, “You should come back and see the children who are here, see how happy they are, and how much weight they’re putting on, and how much they like being here.” And Joe said, “How about right now?” And they said, “Well, not now. Give us a few weeks’ notice and we’ll do it,” which I don’t totally understand. For the purposes of oversight, I think you need to be able to show up when you show up.

TM: Do you feel like you and your office have been able to get all of the answers you want about how this zero-tolerance family separation is working?

The cartels control the crossing points in Mexico, so this guy crossed with his daughter wherever the cartels told him to, wherever he could. And he didn’t try to flee from Border Patrol. He went up to them and said, ‘Hey, here’s what I’m trying to do, help me out.’

BO: No, we don’t have all the answers, and it has been frustrating. This is not out of malice on anyone’s part, or I don’t think there’s any intent to mislead. I really want to stress that Customs and Border Protection, and the actual agents themselves, and the actual CBP officers—they’re doing their best, and everyone that I’ve met from those agencies has been very helpful. I just think that you seemingly arbitrarily and overnight went to a “zero tolerance” policy without having the capacity, the infrastructure, or the systems in place to track kids and make sure they’re reunited with their parents. We know that parents are being deported without their children. We know that parents who are in custody of either the Department of Justice, as they’re prosecuted, or Enforcement and Removal Operations, have no idea where their kids are. I just got in touch with my team and said, “Hey, we’ve got to figure out if the tracking numbers assigned when Border Patrol apprehends follow [and are truly trackable] when a parent is with the Department of Justice and the child is with Health and Human Services.

TM: Have you heard that directly from immigrant parents themselves?

BO: I talked to one of the dads who had been in detention at a privately run detention center in the Rio Grande Valley, run by the GEO Corporation. That was Monday night, so almost a week ago. He had just come here from Guatemala with his twelve-year-old daughter, and at that point it had been five or six days, and he just had no idea if she was alive—and if she was, [no idea] where she was.

This guy had been shot in the back and in the neck. He showed me the bullet wounds. He’s like, “I’ll go back and I’ll die. Just do not send my daughter back there, and if I have to leave her here, if she’s going to be okay, then so be it.” And of course he was not saying it as rationally as I’m saying it now. He was crying, and he was desperate. I just cannot imagine how devastating that feels—to be that dad who’s lived through all that, and successfully brought her to what he thought was safety and then lost her, through really no fault of his own. And I really mean that. I don’t think people know that you have to lawfully present yourself at a point of entry—which, by the way, customs officers are now instructed to prevent you from doing.

The cartels control the crossing points in Mexico, so this guy crossed with his daughter wherever the cartels told him to, wherever he could. And he didn’t try to flee from Border Patrol. He went up to them and said, “Hey, here’s what I’m trying to do. Help me out.” And our response should be, “Okay, you’re petitioning for asylum? Here’s the process: we’re going to keep you with your daughter, and we’re either going to release you to family here, or maybe family detention.” My preference would be that she be released to family, especially when you pose no threat to this country.

TM: Other than publicize this issue, bring attention to it through things like the march, what do you think you can do about this, as a member of Congress?

BO: We have written a bill, and it’ll be introduced this week, that will end the practice of family separation. Everyone is trying to bring Republican colleagues who’ve expressed some amount of shock or dismay at family separation into this effort. Ultimately, it’s going to take both sides to get this passed and force a decision from the administration. That’s the preferable route. The other thing is the administration and their abettors in Congress are proposing to resolve the dreamer [DACA] deportation crisis by guaranteeing temporary reprieve from deportation for dreamers in exchange for changing our asylum laws and, maybe in one version of it, ending family separation. But the way to end family separation, as they say, they will allow you to be held in criminal detention with your children, which—we just don’t do that in this country. We don’t put you in jail with your kids. And that’s one of the proposals going forward.

TM: Are you hopeful?

BO: It’s going to be tough, but maybe what we’re seeing in Tornillo and what we’re seeing in McAllen and other places is going to galvanize the public conscience and force our colleagues to do the right thing. We’ll see.