New Delhi, Aug. 8 -- When Markwayne Mullin suggested in early August that immigration could help compensate for low labor-force participation in some parts of the United States, he was not describing an unconventional economic position. Labor economists have made that argument for decades. What Mullin failed to account for was that he was the Secretary of Homeland Security in a second Trump term, and that the people his department is tasked with removing are the same people whose labor he was publicly acknowledging the economy needed.

a qualifier that, in this administration's history of cabinet departures, has frequently preceded a firing within weeks.

Mullin took office in March, replacing Kristi Noem, who was removed following the de...