Trump is most likely to be replaced with somone with at least nominally the opposite platform. Bush, Clinton, Bush, Obama, Trump, ? is really not more of the same. Hell, he already got thrashed in the last election. It may not look like progress, but people are willing to tackle each sides failures to score points. This tends to remove the absolute dumbest policies.
Mao on the other hand was able to double down and maintain power through the great Chinease famine. This was after a policy of killing off at least one land owner in every village. It’s hard for most people to get just how quickly things can deteriorate without external corrections.