L. Fletcher Prouty describes the operation of the CIA inside government. This is a 6 hour long podcast full of information from an insiders perspective.
CIA sprinkles their employees throughout government. The bosses of any given department move on faster than any of the lower level employees and thus when first placed the boss knows the person is CIA. However when a new boss is installed they are not informed that said employee is CIA. By this method CIA secrets its members all over government. It is also quite evident they end up in congress and given that Bush Sr, Clinton, Bush Jr and Obama were all CIA they end up in the presidency too. This is the secret team.
Book Links: The Secret Team