The idea that the American intelligence community is not political is unrealistic. Senior officials are appointed by the sitting President and owe him some kind of allegiance, although how much depends on the individuals involved. They are probably chosen because their political beliefs or inclinations are similar to those of other senior administration officials, particularly the President’s.
I saw this first hand when I was the State Department representative on a National Intelligence Estimate about the Soviet Union’s military technology (NIE 11-12) that began under the Carter administration and ended under the Reagan administration. Carter’s CIA chief, Adm. Stansfield Turner, was probably somewhat dovish, like Carter. Reagan replaced him with Bill Casey, an old hawkish OSS officer, who had been Reagan's campaign.manager.
As work on the estimate began, the military representatives were very hawkish, wanting to include language that made the Soviets look like technological supermen who were developing high tech weapons that the US would be unable to counter. Although I was not a very senior participant, I began to push back against this, because I did not think the intelligence supported it. The Soviets were indeed working on high tech things that the US was not working on and that we did not understand completely, but that did not justify the conclusion that this research was going to result in weapons that would change the balance of forces between the US and the Soviet Union. As I began to push back, I found I had support from some of the CIA representatives, who were perhaps unwilling to lead the charge against the military reps. But around the time of the election, things changed. The Deputy Director of the CIA, Adm. Bobby Inman, abruptly quit, and of course, Casey replaced Turner. Under Casey, the hawkish views began to be a stronger theme in the NIE. Casey was famous for mumbling, and when I attended the final review of the NIE, chaired by Casey, I was never sure what he said. I would like to think that the NIE came out slightly less hawkish than it would have without my participation, but it’s hard to tell. I think my viewpoint has been supported by what has happened in the 35 years since the NIE. The Soviets or the Russians have still not defeated the US with some kind of high tech doomsday machine.
In any case, the fact that Reagan’s campaign manager took over the CIA illustrates that the CIA is not an apolitical organization. Like the Supreme Court, the CIA reads the newspapers (and a lot of other stuff). Brennan and Clapper are not that political, but as such senior officials they are part of the intense political machinations that make Washington what it is.