Over the past few months, Attorney General Jeff Sessions has faced fierce criticism for his role in the Trump administration’s family separation policy. But while the White House continues to deal with the fallout from tearing kids away from their parents at the border, Sessions has been busy orchestrating another, much quieter attack on the country’s immigration system. Tensions have been simmering for months between the attorney general and the hundreds of judges overseeing immigration courts, but they reached a new high in July. The flashpoint was the case of Reynaldo Castro-Tum, a Guatemalan man who was scheduled to appear...