WRIGHTWOOD DAIRY CO., UNITED STATES v. 315 U.S. 110 (1942) ROCK ROYAL CO-OP, INC., UNITED STATES v. 307 U.S. 533 (1939)

These decisions are among the more significant results of the post-1936 interpretation of the commerce clause as a source of federal power extending to virtually the entire national economy. The agricultural marketing agreement act of 1937 authorized the secretary of agriculture to fix minimum prices for all milk in interstate commerce, or burdening or affecting commerce. In Rock Royal the price-fixing provisions governed sales by local dairy farmers to dealers who processed the milk and transported it. Those opposing federal authority contended that the regulated transactions included intrastate commerce whose sales were fully completed before any interstate commerce began. Holding the statute constitutional, the Court declared that the national power to fix production quotas and prices applied to local milk because its marketing was "inextricably intermingled with and directly affected the marketing of milk which moved across state lines." In Wrightwood, the milk subject to regulation under the same statute was entirely intrastate and none of it was intermingled with milk that crossed state lines. Nevertheless the Court unanimously held that it was the effect on interstate commerce, not the source of the injury to it, that was "the sole criterion of Congressional power." Accordingly, the commerce power extended to intrastate transactions whose regulation made the regulation of interstate commerce effective, including intrastate transactions whose competitive price affected interstate ones. Both cases were decided on a thoroughgoing application of the shreveport doctrine.

Leonard W. Levy
(1986)