The base won't hold this against him, but white Alabamians might. He needed some whites, especially college-educated whites, to win and he'll need them again in 2020.
What? White Alabamians would probably be more likely to vote for him if he votes like a centrist.
Have we tried running a progressive in Alabama?
Funny enough, in Idaho, the last 2 Democratic Senators were progressives. I bet a lot of non progressive Democrats have lost, but they elected Glen Taylor, and Frank Church, the former of whom was actually on the 1948 Progressive party ticket.