text: "Above all, in a democracy, we have the duty to preserve the liberty of the people by keeping the enormous powers of the national government separated.  We are judges, not Platonic Guardians.  It is our duty to say what the law is, and the meta-source of our law, the U.S. Constitution, commits the power to make foreign policy, including the decisions to permit or forbid entry into the United States, to the President and Congress."