Sure, there was the attempted assassination of Reagan and the fears for Obama as the first black President, but in those cases it was a lone nutter rather than a conspiracy.
How long can Trump crash the market before an angry billionaire decides to take him out? The remaining Koch brother is already pouring money into legal challenges against Trump…
It’s important to note that even in that scenario, he’s limited to a total of 10 years. If he would take over from a VP position, he could exceed 10 total years as POTUS.
Whatever “limited” means in the current state of things is another question.