The Warren Court ruled that Congress had the power to pass the Civil Rights Act of 1964 based on its broad powers under the Commerce Clause in two cases: Heart of Atlanta Motel v. United States and Katzenbach v. McClung. The owner of the Heart of Atlanta motel contended that he had the right to refuse to rent rooms to black patrons.

He argued that Congress exceeded its constitutional powers by regulating private businesses. The U.S. Supreme Court noted that there was “overwhelming evidence that discrimination by hotels and motels impedes interstate travel.” The motel owner argued that Congress simply did not have the power to correct what it considered a moral wrong. The motel owner argued that Congress was overstepping and exceeding its constitutional authority in regulating private businesses. The Supreme Court said that did not matter because discrimination in public accommodations harmed interstate commerce: “In framing Title II of this Act Congress was also dealing with what it considered a moral problem. But that fact does not detract from the overwhelming evidence of the disruptive effect that racial discrimination has had on commercial intercourse.”

The second case, Katzenbach v. McClung, involved Ollie’s Barbecue, a privately owned restaurant in Birmingham, Alabama, that limited blacks to take-out service while providing seating to whites in the restaurant’s dining area. The Court reasoned that Congress had a rational basis for concluding that “refusals of service to Negroes have imposed burdens both upon the interstate flow of food and upon the movement of products generally.”