The Trump administration needs to find space to temporarily house migrant children — including the hundreds of children a week being separated from their parents at the border. It’s reportedly considering building a “tent city” on a Texas military base to do it.

The Department of Health and Human Services, which is responsible for taking care of “unaccompanied alien children” — a label that’s also applied to children separated from their parents under the Trump administration’s current “zero tolerance” policy — already has 11,000 immigrants under the age of 18 in its custody who haven’t yet been placed with relatives or other sponsors. Most of those are immigrants, usually teenagers, who came without their parents to the US. But a substantial fraction is children, often very young ones, who were taken from their parents at the border. HHS doesn’t have much more room to take immigrant kids — it’s at 95 percent capacity.

According to a report from Franco Ordoñez of McClatchy, one option the government is considering is to build temporary structures — what McClatchy calls “tent cities” — at one or more Army base in Texas.

It’s a horrific image — Trump putting young children in what critics are labeling “prison camps” — and one that seems like more gratuitous cruelty from an administration that’s not afraid to use cruelty to make its point. But it’s important to understand why the administration is resorting to these measures.

Because of its “zero-tolerance” policy of prosecuting as many immigrants who come into the US illegally as possible, the administration now has to deal with a large and growing population of immigrants in detention — a population it is unprepared to deal with. Trump’s immigration agenda has thrown the system out of whack, and the administration now has to find new, and alarming, workarounds to keep the system functioning.

The Trump administration is essentially offering Congress, and the public, a choice: between allowing children separated from their parents to be held in “tent cities” for a short period of time and allowing them to be kept with their parents in detention centers indefinitely.

The government is legally obligated to hold kids under the “least restrictive” conditions possible

The Trump administration’s adoption of a “zero-tolerance” prosecution policy, formally rolled out in early May, has created a cascade of problems for the immigration system — and escalating public outrage.

First, to accomplish mass prosecution, it needed to start separating hundreds of families a week by transferring the parents into criminal custody and reclassifying the children as “unaccompanied” minors. Then, to accommodate the parents after they were returned to Department of Homeland Security custody (as well as other immigrants who haven’t yet been formally ordered deported), it had to rent space in several federal criminal prisons — putting asylum seekers who are ostensibly in “civil” detention in buildings constructed to house those punished for federal crimes.

Now, it’s looking for space for 1,000 to 5,000 more children, because the number of “unaccompanied” children in HHS custody has jumped by 20 percent now that some children are being taken from the people who accompanied them.

But whenever the government is dealing with immigrant children, it has to abide by strict rules for their treatment.

A court order that’s been in place for decades, known as the Flores settlement, mandates that any immigrant child in custody be placed with a close relative or family friend “without unnecessary delay”; in other words, HHS isn’t allowed to build facilities to house kids indefinitely. Ninety-nine percent of children who come into the US without their parents have close relatives (or family friends) in the US with whom they’re ultimately placed; that number probably isn’t quite as high for kids who come with their parents but have been separated, but some separated children probably do have relatives they can be placed with.

If the government can’t find a sponsor for a child, the Flores order says, they have to keep her in the “least restrictive” form of custody possible.

There’s a lot we don’t know about the government’s plans for new shelters — indeed, we don’t even know whether they’ve decided to build them for sure. And the conditions matter a lot. Any facility that looks more like Sheriff Joe Arpaio’s infamous “tent cities” than it does like a shelter for children is likely to get the government sued. And federal judges have tended to hold the government to a high standard when it comes to the Flores settlement.

The Trump administration wants to keep families together — in immigration detention

The Trump administration really doesn’t like the Flores settlement. In fact, administration officials blame Flores for the fact that they’re separating families to begin with.

The administration’s line on this has been consistent: It would like to be able to detain all immigrants who enter the US without papers until their cases are resolved (and, preferably, resolve those cases as quickly as possible with deportation orders). To the administration, the extra legal protections against indefinite detention of asylum seekers, and much stricter protections under the Flores settlement against indefinite detention of children and families, are nothing but legal “loopholes” that Congress should close.

Keeping families together in immigration detention really would suit the government’s interests. It’s more expensive to keep parents in detention while children are under HHS care (or placed with sponsors or fosters) than to keep both in one detention facility. And now that Attorney General Jeff Sessions’s changes to asylum policy are likely to keep many immigrants fleeing gang violence from passing their initial asylum screenings, the government will be able to deport the whole family together quickly rather than allowing the child to enter the US to pursue a full court case.

If the public is outraged about the construction of “tent cities” to house immigrant children, in other words, the administration is teeing itself up to look like the good guys: They are willing to keep families together as long as Congress passes a law to allow children, families, and other asylum seekers to be detained for as long as it takes until their cases are resolved.

Which is more humane? To take a child from her parent, keep her in a temporary “tent” for a few days or weeks, and then place her with a relative? Or to keep child and parent together, in detention, for months or years?

Most of the administration’s critics would probably answer that the only humane option is to release the whole family together and find another way to monitor their cases to make sure they show up for their court dates. But that is the one option the administration refuses to put back on the table.