If Trump continues keeping his campaign promises - which he seems to have every intention of doing - then it won't matter who the Democrats run in 2020. That assumes the Democrat party doesn't disintegrate when the Republicans win super majorities in both houses of Congress via the 2018 mid-term elections.
The left hates it. They hate it like this:
https://www.youtube.com/watch?v=r1SluSC5JtE