In Pennoyer v. Neff, the Supreme Court delivered a major ruling on personal jurisdiction, which was later upended by the International Shoe Co. v. Washington decision.

The Supreme Court of Pennsylvania sided against Mallory, ruling that consent-by-registration jurisdiction does violate the Due Process Clause of the Fourteenth Amendment to the United States Constitution.

§ 5301(a)(2)(i), (b) (2019) The issue in this case was "whether the Due Process Clause of the Fourteenth Amendment prohibits a State from requiring an out-of-state corporation to consent to personal jurisdiction to do business there".

Justice Ketanji Brown Jackson wrote separately to discuss the precedent of Insurance Corp. of Ireland v. Compagnie des Bauxites de Guinee, 456 U.S. 694 (1982) and explain that the railroad did waive its personal jurisdiction.

Barrett also disagreed that Pennsylvania Fire represented controlling precedent, differentiating it by explaining that in that case, the company had explicitly consented to waive personal jurisdiction.