A citizen challenge to the state Legislative Reapportionment Commission’s final House and Senate maps has “overwhelmingly” shown the commission divided too many political subdivisions, a much-anticipated majority opinion from the state Supreme Court said Friday.

Chief Justice Ronald D. Castille said the petitioners seeking to throw out the maps had made a “concrete showing” that the commission’s plan ran contrary to law, demonstrating the commission split counties, municipalities and wards when it was not “absolutely necessary.”