Also known as: comity interest · comity
Written by attorneys · grounded in primary & secondary sources — see below
A principle of deference requiring one sovereign to respect the judicial proceedings and regulatory authority of another. The principle operates by directing federal courts to abstain from enjoining ongoing state criminal prosecutions absent bad-faith harassment or a patently invalid statute. It likewise guides discretionary abstention decisions in bankruptcy proceedings in the interest of comity with state courts.
Christine Castro organized a protest at a Georgia power plant and faced charges under a new anti-sabotage statute. She asked the federal district court to enjoin the state prosecution on First Amendment grounds. The court declined to issue the injunction because the prosecution was already underway and no evidence showed bad-faith harassment or a statute invalid in every application.
Caleb Chang sued Crown Pharmaceuticals in federal court for patent infringement. Crown had already lost a similar suit brought by another party in a different district. The court applied issue preclusion against Crown after determining that the earlier judgment satisfied due process and that comity supported finality across districts.
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Clifford Cox sued the Florida Board of Regents in federal court alleging age discrimination under a federal statute. The board asserted Eleventh Amendment immunity. The court dismissed the claim, noting that Congress had not validly abrogated immunity and that comity interests counseled against subjecting states to unconsented federal suits.
Chloe Chen purchased shares of a foreign bank on an Australian exchange and later sued the bank in a U.S. district court for securities fraud. The court dismissed the claim because the transaction occurred entirely abroad. It explained that comity interests required restraint in applying U.S. securities law to foreign exchanges.
Curtis Cannon sued Daimler AG in California federal court for injuries occurring in Argentina. The plaintiffs argued that Daimler’s U.S. subsidiary contacts supported jurisdiction. The court rejected the argument, holding that comity interests and due process limits on general jurisdiction prevented hauling a foreign parent into U.S. court for foreign conduct.
Christian Coleman sued a union in federal court under federal labor law and added state-law tort claims arising from the same events. After the federal claim was dismissed, the court declined to retain the state claims. It cited comity interests and the absence of any remaining federal anchor as reasons to dismiss without prejudice.
A federal court must abstain unless the prosecution is brought in bad faith, constitutes harassment, or rests on a statute that is flagrantly unconstitutional with no valid applications. The rule protects comity interests between federal and state courts once state proceedings have begun.
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Yes. Admission alone subjects the lawyer to the state’s disciplinary authority regardless of where the conduct took place. The rule also permits overlapping authority between states that share an interest in the same conduct.
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Yes. Once every claim supporting original jurisdiction has been dismissed, the court has discretion to decline supplemental jurisdiction. Comity interests and judicial economy support dismissal so that state courts may resolve purely state-law disputes.
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…an elementary principle, that the laws of one State have no operation outside of its territory, except so far as is allowed by comity; and that no tribunal established by it can extend its process beyond that territory so as to subject either persons or property to its decisions. "Any exertion of authority of this sort…