Last Month at the Supreme Court | December 2025

Season’s Greetings! The December edition of Last Month at the Supreme Court^®examines cases addressing the limits of judicial power and the finality of federal judgments, alongside a closely watched separation-of-powers challenge to the President’s authority to impose trade tariffs during asserted national emergencies. This docket covers the following questions:

• Whether Federal Rule of Civil Procedure 60(c)(1) limits efforts to set aside default judgments claimed to be void for lack of personal jurisdiction—and more broadly, whether jurisdictional defects at the removal stage can undo final federal judgments years later.
• Whether post-removal developments—such as amended pleadings or the mistaken dismissal of non-diverse parties—can defeat complete diversity and destabilize otherwise final federal adjudications.
• Whether Congress authorized the President to impose tariffs under the International Emergency Economic Powers Act and whether any such delegation satisfies constitutional limits.

Taken together, these cases have meaningful implications for litigation strategy, forum selection, and the scope of executive authority, with downstream effects for regulatory enforcement and business planning.  We invite you to read—or listen to—our concise summaries for insights into how the Court’s decisions may shape both federal practice and the broader legal landscape.

For more information, please contact Chantel Febus, James Azadian, Kyle Asher, Mark Magyar, Monika Harris, Ryan VanOver, David Ter-Petrosyan, or Sadie Betting.

Supreme Court Debates Applicability of Federal Rule to Void Default Judgments

On November 4, 2025, the Supreme Court heard oral argument in Coney Island Auto Parts Unlimited, Inc. v. Burton (24-808) to consider whether Federal Rule of Civil Procedure 60(c)(1) imposes a time limit on motions seeking to set aside a void default judgment for lack of personal jurisdiction.

Read the full synopsis here.  

Supreme Court Weighs Extent of President’s Authority to Impose Tariffs During Proclaimed National Emergencies

On November 5, 2025, the Supreme Court heard oral argument in Learning Resources v. Trump, consolidated with Trump v. VOS Selections (consolidated as No. 24-1287) to consider whether the International Emergency Economic Powers Act (IEEPA) authorizes the President to impose trade tariffs pursuant to declared national emergencies. If the Court concludes that the tariffs are statutorily authorized, the Justices will then decide whether the tariffs constitute an unconstitutional delegation of legislative authority to the President. So far, this is the most important case the Justices have agreed to hear this term.

Read the full synopsis here.

Supreme Court Considers Whether “Final” Judgment Really Means “Final”

In Hain Celestial Group, Inc. v. Palmquist (No. 24-724), the Supreme Court will determine (1) whether a district court’s judgment resolving litigation between completely diverse parties must later be vacated for lack of subject matter jurisdiction if an appellate court subsequently concludes that, at the time the case was removed from state court, the case did not have complete diversity jurisdiction, and (2) whether a plaintiff may block diversity jurisdiction by updating the complaint after removal to include a valid claim against a nondiverse defendant.

Read the full synopsis here.

Grant Alerts

Notable Business Cases the Court Granted Last Month.

Read the full list here.