Commerce Clause

The Commerce Clause gives Congress power "to regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes." It is the constitutional basis for a large share of federal law, from labor and environmental rules to civil rights statutes covering businesses.

For much of early American history the clause was read to cover trade and transportation across state lines. Beginning with the New Deal, the Supreme Court adopted a much broader view. In Wickard v. Filburn (1942) it held that Congress could regulate wheat a farmer grew for his own use because such activity, taken together, substantially affects interstate commerce. Later cases, United States v. Lopez (1995) and United States v. Morrison (2000), drew limits, striking down federal laws on gun possession near schools and gender-motivated violence as outside the clause.

The clause sits at the center of debates over federalism. Conservatives and libertarians generally argue that modern readings have turned a limited power into a general police power the Constitution reserves to the states under the Tenth Amendment. Others argue that an integrated national economy justifies broad federal authority. Courts also recognize a "dormant" Commerce Clause that limits state laws discriminating against interstate trade.