Theory of the monarch or social order
In every nation there are, there has to, be a group of powerful men or women that run things. It has been that way since Sumer. That gives the nation stability and prevents civil war..which no one in power likes as they got a LOT to lose and little to gain. Unless some "upstart " from out side that in-group gets power. Then, until a new balance is restored, chaos breaks loose. That is what happened here in the USA. in 08 and 16. A Bush or a Clintion was supposed to win in 2016. Mr Obama started to upset things in 08 when he took the chair from Clinton that started the shift but his giving her a high place sort of calmed the waters a tad "sort of" as by reports they did not see eye to eye. Mr.Trump did the same when he took the chair from Bush and change accelerated. The whole"resist" movement pushed things into overdrive. Clintion simply could not stand being pushed aside in what she KNEW was her last chance to be President and many "never Trump" types in the GOP hate Mr Trump for pushing Jeb aside,
Bush or Clintion WERE meant to be according the parties the rightful heirs!!!
But in the USA We the people rule.
IF, Trump runs and wins in 2020, thing clam down and balance is restored
So I suspect a Kennedy or a Clintion or a Bush will run to try and take back power.