The Department of Homeland Security is opening makeshift immigration tent courts erected along the U.S.-Mexico border to the public, following months of criticism over a lack of transparency. The department established two such border courts—rows of shipping containers beneath large wedding-style tents—at ports of entry in Brownsville and Laredo, Texas, late this summer. Unlike regular immigration courts and most others across the country, journalists, advocates and other members of the public weren’t permitted to enter. The new acting secretary of the department, Chad Wolf, asked staff after assuming his position in November whether it was feasible to open the courts...