>> their regulations have to fit within restrictions that are defined and may be revised by Congress
This is only notionally true, and history is replete with examples of federal agencies declaring their own authority over things which were obviously not envisioned so. While congress could act to change that, they don't, so power collects.
and history is replete with examples of federal agencies declaring their own authority over things which were obviously not envisioned so
What about in this case? Would you argue the Title 2 declaration is within or not within the FCC's mandate? If you agree it is within the mandate, then bringing up unrelated assumptions of authority is not relevant.
That's because of (1) limited real choices (yay FPTP elections) and (2) most people are negative about Congress, but that's mostly about the members of Congress that don't represent them; people tend to have a lot higher support for their members of Congress (in both Houses) than for Congress as a whole.
This is only notionally true, and history is replete with examples of federal agencies declaring their own authority over things which were obviously not envisioned so. While congress could act to change that, they don't, so power collects.