In a 6-3 decision authored by Justice Amy Coney Barrett, the court granted the government's applications to partially stay the district court's nationwide injunctions in the birthright citizenship cases, noting that universal injunctions "likely exceed the equitable authority that Congress has granted to federal courts." The caveat here is that the applications are granted "only to the extent that the injunctions are broader than necessary to provide complete relief to each plaintiff with standing to sue."
The key to the court's decision appears to be summed up thusly:
When a court concludes that the Executive Branch has acted unlawfully, the answer is not for the court to exceed its power, too.
Additionally, the court has instructed the district courts to "move expeditiously to ensure that, with respect to each plaintiff, the injunctions comport with this rule and otherwise comply with principles of equity."