William J. Brennan,
Baker v. Carr — Opinion of the Court
“ The nonjusticiability of a political question is primarily a function of the separation of powers. Much confusion results from the capacity of the "political question" label to obscure the need for [p211] case-by-case inquiry. Deciding whether a matter has in any measure been committed by the Constitution to another branch of government, or whether the action of that branch exceeds whatever authority has been committed, is itself a delicate exercise in constitutional interpretation, and is a responsibility of this Court as ultimate interpreter of the Constitution. ”
