Harlan F. Stone,
Gwin White Prince v. Henneford…
“ It is as essential today, as at the time of the adoption of the Constitution, that commerce among the States and with foreign nations be left free from discriminatory and retaliatory burdens imposed by the States. It is of equal importance, however, that the judicial department of our government scrupulously observe its constitutional limitations and that Congress alone should adopt a broad national policy of regulation-if otherwise valid State laws combine to hamper the free flow of commerce. ”
