Given the state of gerrymandering, voter suppression and the electoral college, the Democratic base alone is insufficient for victory.
But that does not mean attempting to appeal to soft Republicans; the tiny numbers of potential Trumpist defectors are massively outweighed by the huge population of non-voters. Most of whom are to the left of both parties, particularly when it comes to working-class economic issues.
Any attempt to appeal to soft fascists, or the continuation of policy driven by corporate cash, is going to keep those voters at home.
If middle class America continues to refuse to support the interests of working class America (which includes most of Black America), then working class Americans are not going to save the American empire from destroying itself.