I mean, there are plenty of Democratic voters that are "okay with white nationalism" also!
A sample. Should we start kicking them out of the voting booth? Where does this idea come from that I somehow need to like or "trust" the people that vote for the same candidates I do? Progressives just need more votes, not more "friends". If I (not me personally, but the national Democratic party as an organization) can convince some white nationalist (or someone who's just passive/ignorant of white nationalism, which is far more numerous) to vote for a progressive, antiracist candidate, because you can appeal to some other part of their self-interest, and that keeps right-wing Republicans from getting into office, why wouldn't I try that?
I'm not sure what your actual end goal is. Most Clinton supporters spent the past year talking about "pragmatism" and "acknowledging political reality" and rejecting "moral purity", yet the argument now seems to be "we should make sure no one gives any inch to racism first, before we allow them to vote for our candidates"? I mean, that's fine and all, but I can't see too many elections being won with the strategy of "if you've remotely held any sort of racist view or even just casually ignored a racist view, I don't want you voting for my candidates".
Never mind the fact that Clinton's support was down in a lot of areas among her supposed "firewalls", latinos and black folks, so chalking that up solely to white supremacy seems odd.
Maybe the confusion is that you think the only possible way to reach Trump voters or non-voters is with racism, so you're thinking Democrats will have to compromise on antiracism/antisexism/etc. to win elections from now on? I guess if you think that's true, I'd understand your reaction.
But then Obama's campaign literally did what you're saying is "not very convincing", and he was able to win a couple elections, so I don't quite understand this idea of "we can't have any racists voting for us!" Do you think people who voted Democrat in 2008-2012 were purely progressive people who were all free of racism, sexism, and homophobia?