West Lynn Creamery, Inc. v. Healy

To help struggling Massachusetts dairy farmers compete against lower-priced out-of-state milk, the state imposed a tax on all milk sold to Massachusetts retailers, then redistributed the proceeds entirely as a subsidy to in-state dairy farmers; out-of-state dealer West Lynn Creamery (plaintiff), which paid the tax but received no subsidy benefit, challenged the scheme as discriminating against interstate commerce, and lower Massachusetts courts upheld it.

Whether a state law violates the Commerce Clause when the combination of a tax and a subsidy discriminates against interstate commerce, even though each component might be constitutional standing alone.