Central American asylum seekers wait as U.S. Border Patrol agents take them into custody on June 12 near McAllen, Tex. (John Moore/Getty Images)

THE FAMILY-SEPARATION crisis that President Trump created is not over. The executive order Mr. Trump signed Wednesday purporting to end the routine tearing of children from their undocumented parents stands on uncertain legal ground. U.S. border agents took more than 2,300 children from their families during a five-week period. Confusion mounted Thursday about the status of the root problem: Mr. Trump’s zero-tolerance policy at the border. And a failed immigration vote in the House underscored that Speaker Paul D. Ryan (R-Wis.) and his Republican majority remain a long way from useful or humane legislation on the immigration issue.

The executive order shifted Trump administration policy from separating children when their parents are sent off to detention to keeping children with their families as they are all placed in custody. Practical and legal questions abound. Where would these families be held, given that detention facilities are already packed? Will a judge allow the administration to hold children longer than 20 days as their parents await hearings, the limit currently prescribed by judicial decree? It seems unlikely; why would a judge approve the indefinite stockpiling of families in federal custody simply to enable federal authorities to prosecute parents on minor misdemeanor charges of illegal border-crossing?

Meanwhile, the government must reunite the families it has already split. Mr. Ryan assured reporters Thursday that the Department of Homeland Security and the Department of Health and Human Services were working to put children back in their parents’ care, while placing the adults’ cases first in line for adjudication. Yet U.S. Customs and Border Protection indicated Thursday that the children will be kept apart until their parents’ prosecutions are settled. The nightmare scenario remains entirely too realistic: that some children and parents remain forever separated as a result of the administration’s bureaucratic bungling and hasty implementation of its zero-tolerance policy.

A partial answer to most of these problems is backing off that policy. Not every illegal border-crosser must be held in custody pending prosecution. It would cost less, and it would avoid inevitable humanitarian problems, if people were released and fitted with ankle bracelets or subjected to other types of monitoring. According to NPR, Immigration and Customs Enforcement (ICE) reports that 99.8 percent of undocumented immigrants released with this sort of supervision show up for their court dates. Warehousing families simply is not necessary.

Temporarily acquiescing to this reality, a senior U.S. Customs and Border Protection official told The Post on Thursday that the agency would stop referring illegal border-crossers with children for prosecution — but apparently only until ICE had proper facilities in which to hold families. Yet the Justice Department said the zero-tolerance policy had not changed. And the president insisted with his habitual false and scaremongering rhetoric, “If we take zero-tolerance away . . . we would be overrun.”

Capping a confusing day, the House on Thursday rejected a hard-line immigration measure and postponed until next week a vote on a more moderate yet still unlikely-to-pass bill. Each would address child separation and the fate of the “dreamers” — but at the price of big concessions to Trumpian immigration restrictionists. Yet that is not what the country needs or what most Americans want.

Congress should pass a bill barring a return to Mr. Trump’s barbaric policy of child separation. It should give the “dreamers,” young immigrants brought here at a young age through no fault of their own, a path to citizenship. It should reject the demonization and division that Mr. Trump seeks to use to his political advantage.