And what you call "white nationalism" (what I would call "Anglo-Americanism") is their culture.
So, what do you expect a people-group to do when you intend to destroy them as a culture?
Or, if you see that they believe you intend them as a culture, but that's not actually your intent, then how do you change your rhetoric to make them understand your actual intent?
This is where I would point to my earlier remarks about sussing out their actual beliefs and their actual motivations vs the ones they claim to espouse.
Sure, for some segment of this group, white nationalism has been their ideology for a long time. But for others, like Elon Musk, it's pretty new. I've not been shy about my low opinion of him the last several years, but he hasn't always been this way. Or at least, if he's always been a jerk, his jerkiness hasn't manifested itself in this way until fairly recently. I've heard some insider pundits point to his snubbing by the Biden administration over some EV summit as an inflection point for his political affinities.
The fact that so many of these people are johnny-come-latelies leads me to believe that, in their cases, the white nationalism is merely filling some other void, and if you go about pandering to the white nationalism, you're not going to get anywhere except to a place where that ideology is seen as more legitimate.
If I were to play armchair shrink for Musk, I'd describe him as sort of an engineer's version of Trump: He's demonstrated an ability to get some things done; pretty well, in fact. But he's also got a long history of sticking his nose into places it doesn't belong and making self-aggrandizing proclamations on which he can't/won't/doesn't follow through. My guess is he's got some sort of god complex and is looking for reverence for his ability to transcend humanity's problems and becomes petulent when he's denied the control or respect he thinks he's due. When Biden chose the UAW over him at the EV summit, he got butthurt and shifted hard to the right, where folks are more inclined to afford him the adulation he wants. If I'm correct, then winning him back to the left would require pandering to the god complex, not to the white nationalism.