Indeed, while the data released Thursday showed progress on the overall flow of people and on children traveling unaccompanied by parents, the number of families trying to sneak into the U.S. between the ports of entry remained virtually unchanged over the past three months.

Analysts were baffled. They expected the administration’s get-tough policy announced in early May to change patterns.

The administration’s zero-tolerance policy was supposed to scare migrants — families in particular — away from attempting to sneak into the U.S.