“ Our well-established practice of a remand for consideration in the light of a subsequent decision therefore applies. As in Scholle v. Hare, 369 U.S. 429, 82 S.Ct. 910, we believe that the court below should be the first to consider the merits of the federal constitutional claim, free from any doubts as to its justiciability and as to the merits of alleged arbitrary and invidious geographical discrimination. ”

“ A second opinion expressed the view that since the apportionment was not alleged to effect a discrimination against any particular racial or religious group, but merely a geographical discrimination, jurisdiction should be exercised, but only to dismiss. 202 F.Supp., at 754. A third opinion rested on the ground that the action was not justiciable and expressed no view on the merits. ”

“ Carr, 369 U.S. 186, 82 S.Ct. 691, 7 L.Ed.2d 663, that a justiciable federal constitutional cause of action is stated by a claim of arbitrary impairment of votes by means of invidiously discriminatory geographic classification. ”