"The Commerce Clause of the United States Constitution provides that the Congress shall have the power to regulate interstate and foreign commerce. The plain meaning of this language might indicate a limited power to regulate commercial trade between persons in one state and persons outside of that state. However, the Commerce Clause has never been construed quite so narrowly. Rather, the clause, along with the economy of the United States, has grown and become more complex. In addition, when Congress began to address national social problems, the Commerce Clause was often cited as the constitutional basis for such legislation. As a result, the Commerce Clause has become the constitutional basis for a significant portion of the laws passed by Congress over the last 50 years, and it currently represents one of the broadest bases for the exercise of congressional powers."
CRS Report for Congress, RL32844