How you think Congress and the administrative agencies should relate to each other really depends on your theory of administration, both as a matter of Constitutional Law and as a matter of policy. If you are a devotee of the Constitution of 1788, you will think that it's Congress's job to make the major policy decisions. That's what the legislative power is. The job of agencies would be to implement those legislative decisions under the direction of the President. And if the agencies exceed their power, Congress, the Courts, the President, or all three should smack them down. So that relationship would be dictated by a vision of the constitutional allocation of powers. That particular allocation of powers is somewhere in the toilet. What do we do now? Well, that to some extent depends upon your vision of proper administrative policy. If you believe, as the Progressive Era believed, that the legislature should set the general policies and then leave the agencies free to implement, Congress's role would expire once it lays down in the statute what the agencies are supposed to do. You would not want politicians micromanaging the technical experts. If you believe in the New Deal model of administration, you wouldn't even want Congress to set the policies. You'd want Congress to pass a law that says, "Here's the agency, here's the agency's budget. Go forth and do good," which by the way, is what a non-trivial number of the actual statutes enacted during that period essentially say. Congress' role in that would be to keep the money flowing to the agency so that it can do its job. Fast-forward to the 1960's. If you worry that agencies aren't going to be technocraticly pursuing an objective public interest, but instead are going to be selling out to the highest bidder or pursuing their own agendas, then there's something to be said for Congress keeping an eye on the agencies, both by drafting more specific legislation, and also to some extent, by micromanaging the way in which the agencies carry those functions into effect. Through oversight hearings, through making budget hearings actually something that involved an assessment of agency performance. Fast-forward to the present. Just ask yourself whether you think, and whether there's anything wrong with thinking, that the proper relationship between Congress and agencies depends on who's in Congress and who's in the agencies. If you like the President and you like the people that the President is appointing to the agencies, do you have a different view about how carefully you want Congress to scrutinize what the agencies are doing than if you don't much like the President, you don't much like the agencies, and you think the agencies are going to be pursuing policies that you don't like. And is there anything wrong with having your view of the proper Congress/agency relationship depend upon things like that?