Federal judge Trevor Neil McFadden on Thursday ruled that the Trump administration could go ahead and require all illegal immigrants to register and carry documentation. The requirement became effective on Friday. The Coalition for Humane Immigrant Rights and other co-plaintiffs had sought a stay and injunction pausing enforcement of the rule. McFadden’s opinion focused on the plaintiffs’ lack of standing. He said the plaintiffs could not prove their arguments that the registration rule significantly harmed their operations as well as illegal immigrants’ speech rights. What does the rule require? Illegal immigrants must register their addresses and fingerprints and must carry...