The recent Trump case was one of the most eye-opening and confusing judgments I've read. For context, Trump signed an executive order to re-interpret "birthright" citizenship limiting it to children born in USA by at least one parent with US citizenship. A couple district courts ordered preliminary injunctions against its enforcement. The government eventually argued to the Supreme Court that the preliminary injunctions were too broad in scope. The court with an apparently 6:3 majority decided that the lower courts had no right to award "universal injunctions" beyond the scope of the plaintiffs seeking the injunction. Federal courts' power to issue injunctions apparently stems from the Judiciary Act of 1789, which endowed federal courts with jurisdiction over "all suits... in equity". This is nothing exciting, except that the USSC then declares that the scope of "equity" is basically the jurisdiction of the High Court of Chancery in Engla...