A few words giving Congress power over trade between the states have quietly become the basis for a startling share of all federal law, from civil rights to the food on your plate.
The Commerce Clause, in Article I, Section 8, gives Congress the power to regulate commerce among the several states. On its face it is about trade crossing state lines. In practice it has become one of the broadest grants of federal power in the Constitution.
Its reach expanded enormously in the twentieth century. Courts read commerce to include not just goods crossing borders but almost any activity that, in the aggregate, affects the national economy, even a farmer growing wheat for his own use.
That breadth made it a tool for far more than trade. The Civil Rights Act of 1964 banned discrimination in hotels and restaurants partly on commerce-clause grounds, reasoning that segregation burdened interstate travel and business.
It is also a recurring battleground. Critics argue the clause has been stretched past recognition, and the Supreme Court has at times pulled it back, making the true limits of the commerce power one of the most consequential open questions in constitutional law.
