Really it's a question of where the threshold lies.

The American President is quite elderly, clearly diminished, and the ravages of age are inescapable no matter how beloved you are. However much Americans seem happy to tolerate his particular brand of authoritarianism, the horizon on his rule cannot realistically be more than a decade out.

Is that enough time to consolidate power? If not, is there a successor who can complete his objectives?

Neither seems clear to me, and one can at least imagine a world where things tick back after he exits the political stage.