The founders were extremely concerned with the promotion and regulation of commerce. Commerce being the buying and selling, trading, movement and transport of goods and people from one place to another, which were necessary in order to provide for economic prosperity. There was, of course, three types of commerce that were covered by the national powers of the Congress, one was the power to regulate commerce with foreign nations. Secondly, the power to regulate commerce among the several states, and thirdly commerce with Indian tribes, leaving a fourth category of commerce that was not given to Congress to regulate and that was commerce that existed wholly within a state. Once you realize that commerce connects the entire country together and anything that affects interstate commerce could include just about anything in the country. As soon as you move beyond the regulation of commerce to the regulation of activities that affect interstate commerce, that is going to greatly, greatly increase the powers of the national government. The two principal sources of the powers of the federal government that go beyond the original powers, for example to provide for a strong national defense, are the powers to regulate commerce and the power to tax and spend. Between those two powers, Congress has been able to regulate or prohibit just about anything it wants to.