Why Was I Wrong on Trump's Power Over Agencies?

After Trump had been elected president, I remember pontificating to a cousin and his family about the way the deep state would limit Trump's impact, except I was talking in terms of the "iron triangle".   That was conventional wisdom back in the 1960's--the idea being that a combination of the bureaucrats in an agency, the members of Congress on the committees overseeing the agency, and the interest groups lobbying the members and the agency formed a powerful "iron triangle".

With that understanding I've been surprised by the Trump administration's ability to overturn a lot of regulations in a number of different agencies.  So what happened?

A number of things have changed over the last 60 years:

• There's a lot more regulation and regulatory agencies, for one thing, and agencies which existed in the 1960's have been given more regulatory responsibilities.  EPA and OSHA are just two of the new agencies, and FSA/NRCS are an example of the added regulatory authority. I think there's a lot more generalized hostility to regulation now than there used to be, partly because of this expansion.  
• In the 1960's the discussion was more about the ICC or CAB, two agencies which were eliminated in the Carter/Reagan deregulation effort.  In those cases there had been "regulatory capture"; the agencies served the interests of the regulated, less the general public.
• In the 1960's there was a general faith in government, which carried over to endorse the validity of agency regulation. That was one aspect of LBJ's Great Society.  But while the faith was sufficient to create the agencies, it didn't result in forming interest groups which could effectively power the agencies as envisaged in the "iron triangle" theory.
• In the 1960's committee chairmen were powerful, Congressional leadership not so much.  That meant the chairmen could get their way reasonably often, despite the opposition of the President.  With the Gingrich revolution the chairs have diminished power.