When agencies engage in rule-making, what they do looks very much like what Congress does when it passes a law. The thing that emerges from that process, the rule, has the same legal effect as a statute. It's enforceable in court, it can create criminal penalties, civil penalties, can preempt state law. All of the things that a statute can do, a rule can do. What's the difference? Well, there's a very large difference in the process, the procedure by which those different legal norms are produced. Congress produces laws. The Constitution, in Article One, Section Seven, specifies a process by which those laws are made. So that process is very cumbersome. It's designed to bring into play at least three bodies with different constituencies: the House, the Senate, the President. There are a lot of what political scientists call veto points built into that process. A lot of ways to derail legislation on its way to becoming law. It can be stopped in the House, it can be stopped in the Senate, it can be stopped in committees, it can be stopped at the level of the President. Each of those ways of stopping something from becoming law is a veto point. Now, shift to agency rule-making. Agency rule-making loses those constitutional veto points. For an agency to promulgate a rule, all you need is a majority of the agency. If there's a single head of the agency, that's one person. If it's a multi-member commission of let's say five people, you need three of them. On the other hand, there are certain procedures or hoops that agencies have to jump through that Congress does not. Administrative agencies engaged in rule making that's going to result in these rules that look and act like statutes, by statute have to jump through a whole bunch of hoops. They do have to provide advanced notice of what they're doing. They have to give people an opportunity to explain why what they're doing is a bad idea. Once they do it, they have to explain what they did. Once Congress enacts a law, it doesn't have to write an essay explaining why the law it passed is such a great idea. When administrative agencies promulgate rules, they have an essay requirement that comes with it. They have to write a long, detailed explanation that is going to be looked at by a court, to make sure that they haven't skipped any steps in their reasoning. Just like on a math test, agencies have to show their work. So there are procedural obstacles to agency rule-making that don't exist for actual law making, but they're different kinds of procedures. They're not the procedures identified in the Constitution for the promulgation of legally binding norms. But substantively, once all the hoops have been jumped through, once all of the procedures have been followed, an agency rule is just as potent a legal instrument as a statute.