IANAL, but I am a 3rd year law student and I know alot about this topic.
This is the way the US government gets around the US constitution:
Congress gets power to regulate ALMOST ANYTHING THEY WANT by the Interstate Commerce Clause. The supreme court has essentially explicitly allowed this since the New Deal era. In fact, since the 1940s there are only probably a handful of cases where the Supreme Court deemed something to be unconstitutional via the interstate commerce clause- almost every other time they say that it falls within interstate commerce and they can regulate it. This is the basis of regulation of Drugs, guns, etc. of which the authority was not granted to them by the US constitution.
In addition, the current body of administrative law basically allows organizations like the EPA, the FCC, the FDA, the FTC, the SEC etc. to make their enforceable laws because they are organizations created by a congressional statute, and therefore are supposed to an "extension" of congress itself. Now, do not quote me on that. They are NOT a direct extension of congress and there are THOUSANDS UPON THOUSANDS of pages with legal discussion of the non-delegation doctrine. [the idea that congress can't shuffle it's responsibilities to another branch of government or another organization]. However, for all intents and purposes, the non-delegation doctrine is dead and these organizations are allowed to make law.
This is the country we live in today.
Cynical moment: The only thing that law school has taught me: the US constitution is fucking dead.