In his blog post, Dominic Cummings (former advisor to Boris Johnson) writes the following:

In Washington as in London, the golden rule of Government is — the government does not control the government and anybody who tries to change this is seen as the enemy by the bureaucracies that actually control ~99% of the government. Politicians talk as if the government controls the government and fundraise as if it does. The media reports as if it does. It does not.

He goes on to explain the difficulties faced by British and American politician in trying to push through their agenda, such as the FBI taking a long time to issue security clearances to Trump's appointments. Is there any academic research into this concept? I presume Cummings wasn't the first person to come up with this idea.