That's a good point that a large share of Trump's base simply loathes the opposition. This is a natural result of Obama's constant mockery of that group. Ever since I was a lad, there has always been a large share of voters who vote against people, as opposed to for them. Obama exacerbated that with his divisiveness.
I'm not seeing a sign the Dems are prepared to counter that, not when I see them floating names like Liz Warren and Kamila Harris as possible candidates for 2020. People hate them, too, or will as soon as they start their spiels.