As it stands right now with the economy doing so well, IMHO it will take a major recession/depression scenario to derail Trump in 2020. I wonder how many dems are hoping for just such a thing. Bill Clinton had it right"it's the economy, stupid". It's almost always the economy. People doing well are not looking for any kind of change yet alone a radical one. Things may change in 2 years but for now I see no one that can beat Trump in 2020.