That's very interesting.
I've always thought all the presidents "know" . We once joked that was why they went in looking young and shortly thereafter, looked aged. What they learned was so shocking.
We can bet our behinds there are agencies we have no clue exist.
As to your last question, I think it's the control issue. Humans are pretty adaptable beings.
imo
I don't believe all the presidents know. I think there are black projects and funds they are kept in the dark about. Basically I believe the president is kept in the dark about lots of things. IF there is a UFO cover-up of Roswell.
I think most people, especially Americans are sheep and prefer to remain ignorant and will believe anything they are spoon fed by the media. Either way the media has people believing those that see UFOs are whack jobs and weather balloons and swamp gas are the real explanations....or ...it's the media driving the conspiracy theory.
I so wanted to believe in Roswell incident and Betty & Barney Hill and I used to think Stan Freeman was the coolest........... But after lots of reading, I hate to have to say, I'm not buying what they are saying. I WANT to believe there is intelligent life out there and they may have visited, but I haven't seen any proof yet....haven't seen any proof of God either. I think aliens are the "new God" for many. Until I see the mothership hovering over my house and it's close enough to look like the one in Independence day..I am gonna have to say No.