It subordinates evidence to an overriding and unfalsifiable belief that the truth is deliberately suppressed. Someone who holds that view is not safe in the world of public policy and is not competent to hold executive office.
Here‘s one theory which Oliver no doubt thinks appalling:
I say this not to defend Ms Palin - though note that Oliver gives us no evidence that she believes this conspiracy - but rather to make a point about the nature of rationality.
Possession of rationality is not a binary 1-0 property; it’s not something one either has or not. Instead, we are all irrational in some contexts - though rarely in all. There are no general-purpose experts.
Few of us would infer that scientists automatically have political opinions worth believing. So why should we believe people who are irrational in one respect - if that's what Ms Palin is - are unfit for office? I find it possible - in theory - to believe that someone can be a creationist, and yet rational in other contexts.