I understand the interest in such speculation, but the Democrats first need a solid candidate that is electable and appeals to most middle class voters. The gerrymandering is going to be tough to beat and Trump could win again in the Electoral College while loosing the popular vote.
One thing is pretty clear to me. Anyone who favors Trump in any way today will vote for him in the next election no matter what he says, no mater what he does, and no matter if these same voters are hurt by his policies and Executive Actions. They will vote for him, period.
I think the bigger question is, who didn't vote in the last election, and will they vote in the next one?