President Trump’s recent executive order ending the unlawful and immoral policy of separating children from their parents advances another, equally lawless policy: prolonging the detention of families seeking asylum.

In his June 20 order, Mr. Trump pinned the current crisis on bad law, specifically citing “Congress’s failure to act and court orders.” On Sunday, the president went even further, suggesting that the United States suspend due process for undocumented immigrants altogether: “When somebody comes in, we must immediately, with no judges or court cases, bring them back from where they came.”

The problem, of course, is neither United States law nor the Constitution. It is the administration’s belief that both can be ignored. As long as this administration pursues a deterrence policy predicated on inflicting harm on children and families and disregarding settled constitutional principles, the crisis will continue.

The president’s executive order is silent on how to help the more than 2,000 children, including infants and toddlers, who have already been separated from their parents and are now in federal custody. Held in an estimated 100 shelters around the country, these children remain in limbo, with no plan for reunification. The longer they are separated from their parents, the more severe and indelible the psychological toll. The continuing separation violates the constitutional guarantee of family integrity, which prevents the government from taking children from their parents without due process.