And the reasons this did fail:
1. Two reasons. a) too optimistic b) Kim is the smarter negotiator
2. Naive. And now juridical means to live up to that promise
3. Of course the Democrat party would not allow themselves to be blackmailed.
4. Hard one, as I'll need to dive deeper into that. Quote from wikipedia: "the reference day used for the census, will be April 1, 2020" -- Okay, let's deem it an April Fools Joke :P
5. I think that threat rather convinced them they SHOULD buy those missiles from Russia rather than to convince them NOT to do that... The logical (or at least most obvious) response to an international threat is arming your country. Not always the best response, but one that is mostly being chosen for.