[SkyMarshal]

>Perhaps it was power that corrupted him or maybe it was his close advisors that stymied his original purer motives.

I think it's more likely that the Federal bureaucracy is simply more powerful than our elected officials, at least some ways. They provide a great deal of the information Congress and the President use to inform their worldviews and decisions, and probably have well developed methods of getting what they want from the two. The bureaucracy has a real advantage by simply having less turnover, more continuous time in the system, hence more institutional knowledge of how to work the system, than the average politician.