Fact-checking Justice Sotomayor’s imaginary birthright citizenship cases

Last week, the Supreme Court held oral arguments in Trump v. CASA, Inc., a case that stems from President Donald Trump’s January executive order on birthright citizenship. At this point in the litigation, the court isn’t addressing the constitutionality of the order itself, but instead will resolve an important procedural question over the power of lower federal court judges to issue “nationwide” injunctions.

Nonetheless, during the arguments, Justice Sonia Sotomayor made an assertion about...