Paraphrase

The Commerce Clause refers to Article 1, Section 8, Clause 3 of the U.S. Constitution, which gives Congress the power "to regulate commerce with foreign nations, and among the several states, and with the Indian tribes. Congress has often used the Commerce Clause to justify exercising legislative power over the activities of states and their citizens, leading to significant and ongoing controversy regarding the balance of power between the federal government and the states. The Commerce Clause has historically been viewed as both a grant of congressional authority and as a restriction on the regulatory authority of the States.