The state suit reached trial first, and the jury returned a huge verdict for Exxon Mobil, totalling over $400 million.

The Third Circuit raised, sua sponte (on its own motion), the issue of subject-matter jurisdiction, and concluded that the Rooker-Feldman doctrine precluded the district court from proceeding, on the grounds that Exxon Mobil's claims had already been heard in state court—even though Exxon Mobil was not seeking to have the state court verdict overturned.

Justice Ginsburg, writing for a unanimous Court, reversed the Third Circuit's decision and remanded the case.

She began her decision with a fairly concise retelling of the holdings in both the Rooker and Feldman cases.

She then held that the Rooker-Feldman doctrine is confined to cases of the kind from which the doctrine acquired its name: cases brought by state-court losers complaining of injuries caused by state-court judgments rendered before the district court proceedings commenced and inviting district court review and rejection of those judgments.