A tent encampment near the U.S. Customs and Border Protection port of entry in Tornillo, Tex., as seen from Guadalupe, Mexico, on Sept. 12. (Jose Luis Gonzalez/Reuters)

LIKE AN electrocardiogram or a stock ticker, filings in a California federal court case known as Ms. L. vs. U.S. Immigration and Customs Enforcement provide a real-time and precise gauge — in this case, of the residual but ongoing cruelty visited upon children by the Trump administration’s family separation policy. In its fully realized form, that policy lasted just six weeks, but its remnants — in trauma inflicted, lives upended and tears — live to this day.

More than three months after President Trump signed an order ending family separations, hundreds of children separated from their parents by U.S. officials remain apart. In the case of more than two-thirds of them, their parents were deported — often without knowing how or whether they might be reunified with their children.

At this point, the parents of dozens of the children have waived reunification, opting to have their children pursue asylum cases in the United States. Several dozen more separated children have parents who are still in the United States; most are expected to be rejoined shortly. In about 100 other cases, however, the children remain separated from deported parents. Some may be rejoined in the coming weeks, but the majority have parents who have not been located, or for whom no phone numbers have been found, or from whom information is incomplete.

Think of that number — about 70 by a running total compiled by the American Civil Liberties Union — as a Separated Families Misery Index (SFMI). True, the SFMI has been whittled down from more than 2,500 children systematically ripped away from their parents starting in April, before the president ordered the practice halted in June. But each of those remaining children represents an indictment of the administration’s zero-compassion policy.

The progress made in reunifying children with their parents has been made thanks largely to the ACLU, whose lawsuit in the case of Ms. L., a Congolese woman whose 7-year-old child was ripped from her arms last year, galvanized outrage against Mr. Trump’s policy, and to a handful of nongovernmental organizations that are doing the thankless work of tracking down parents, often in remote areas of Central America. They, not government officials, have been tasked with fixing the mess created by the administration, which tore families asunder with no plan to reunify them.

That cavalier cruelty is typical of an administration that also has shipped hundreds of children, mainly teenagers, to a remote tent encampment in West Texas, where they are warehoused for weeks at a time, awaiting placement with sponsors, without schools or other age-appropriate support. As the New York Times reported, the population of detained children at the tent camp in Tornillo, Tex., has swollen despite the fact that border crossings have been steady in recent months. That’s because sponsors with whom the children would have been placed in the past — in many cases, undocumented immigrants — have been scared away by the administration’s threats and policies. ICE last month acknowledged arresting dozens of people who applied to be sponsors.

Children, parents, sponsors — all are candidates for cruelty at the hands of an administration carrying out a crusade against immigrants, a policy that diminishes the nation.