More than fairly obvious. The military records show that he was definitely diagnosed as having mental problems.
Yes, but as Lambert pointed out he had a lot of people going along with him. It wasn't just him.
If you read the notes/accounts of the conferences he had with his assistants/staff, it's bizarro land. He makes these outrageous claims - based on the latest "witness" he met or heard from - and everyone else in the room just goes along. Even though the latest claim is completely at odds with what he claimed the month before. A few of his people got fed up and left; but most of them just merrily went along.
As a side note: I know we don't want to get into politics here but Donald Trump sounds a lot like Garrison. Sorry to the Trump supporters but that's how I see it.