Let us speak plainly about Trump v. Barbara, the Supreme Court’s upcoming case on birthright citizenship. Many of the high court’s cases are about arcane legal doctrines or complex federal statutes. Real-world effects can sometimes be difficult to discern through the time-consuming labyrinth of appellate review. Rarely does the court decide anything that immediately changes everything.The birthright citizenship case is different. It is both more real and less abstract than any other case on the...