6 RUCHO v. COMMON CAUSE Opinion of the Court voters out of the Sixth District and moving 350,000 new voters in. Overall, the Plan reduced the number of registered Republicans in the Sixth District by about 66,000 and increased the number of registered Democrats by about 24,000. Id., at 499–501. The map was adopted by a party-line vote. Id., at 506. It was used in the 2012 election and succeeded in flipping the Sixth District. A Democrat has held the seat ever since. In November 2013, three Maryland voters filed this lawsuit. They alleged that the 2011 Plan violated the First Amendment, the Elections Clause, and Article I, §2, of the Constitution. After considerable procedural skirmishing and litigation over preliminary relief, the District Court entered summary judgment for the plaintiffs. 348 F. Supp. 3d 493. It concluded that the plaintiffs’ claims were justiciable, and that the Plan violated the First Amendment by diminishing their “ability to elect their candidate of choice” because of their party affiliation and voting history, and by burdening their associational rights. Id., at 498. On the latter point, the court relied upon findings that Republicans in the Sixth District “were burdened in fundraising, attracting volunteers, campaigning, and generating interest in voting in an atmosphere of general confusion and apathy.” Id., at 524. The District Court permanently enjoined the State from using the 2011 Plan and ordered it to promptly adopt a new plan for the 2020 election. Id., at 525. The defendants appealed directly to this Court under 28 U. S. C. §1253. We postponed jurisdiction. 586 U. S. ___ (2019). II A Article III of the Constitution limits federal courts to deciding “Cases” and “Controversies.” We have understood that limitation to mean that federal courts can address only questions “historically viewed as capable of