Baker v Carr 369 US 186 (1961)

The plaintiffs, each one been qualified to vote for members of the Tennessee legislature representing his county, instituted a class action for a declaration that the Tennessee Apportionment Act of 1901 was unconstitutional. The plaintiffs alleged that the act violated the constitution in its disregard of the standard of apportionment prescribed by the state’s constitution or any standard thereby affecting a gross proportion of voting population. The District Court said that it lacked jurisdiction of the subject matter since it was a political question and therefore non justiciable, the USSC reversed the judgment

The mere fact that a suit seeks protection of political rights does not mean that it presents a political question and is therefore nonjusticiable. Where federal judicial relief is withheld on the ground of inappropriateness of the subject matter for judicial consideration (nonjusticiability) as distinguished from lack of federal jurisdiction, consideration of the cause is not wholly and immediately foreclosed; rather the court’s inquiry necessarily proceeds to the point of deciding whether the duty asserted can be judicially identified and its breach judicially determined, and whether protection for the right as asserted can be judicially moulded.