One of the challenges with Trump v. CASA is accounting for nearly a century worth of Supreme Court decisions. There are a host of landmark decisions where the Court arguably approved of universal injunctions, such as Pierce v. Society of Sisters and West Virginia v. Barnette. Mili Sohoni says these were universal injunctions. Mike Morley disputes these accounts. Justice Barrett discounts these "drive-by" remedial rulings as modern cases that postdate the Judiciary Act of 1789 by more than a century. Justice Sotomayor also cites Brown v. Board of Education II, which proposed some very unusual equitable remedies with "all deliberate speed." Barrett does not respond to Brown. The harder case, in my view, would have been the equitable remedy for Bolling v. Sharpe against the federal government.
But one case where the majority and dissent do engage each other is Ex Parte Young, the classic FedCourts case.
Justice Sotomayor argues that Young is evidence that equitable jurisdiction is not trapped in amber, but instead evolves over time: