OP is wrong about unrestricted access to all weapons. And not all Republicans are anti-abortion, although that is a big part of their platform due to the control it gives over evangelicals. (That is to say, I think if there is a schism, the more centric version of the party would not be anti-abortion.)

Also, white nationalism is only embraced by a small percentage of the party. It's not really part of their platform, it's just what the loudest shouters in the party want.

(Disclaimer: I do not identify as repbulican, but if this is your best faith effort to define their platform, you lack empathy for them which means you'll never understand even their lucid ideas. Granted, many of their ideas are vague and not lucid.)

> whose primary concern is one of...

I'm not saying that all Republicans are white nationalist and anti-abortion but I haven't met a Republican whose primary political concern wasn't one of the issues I listed.

And everybody I've met whose primary issue is one of those that I listed has been Republican.

The vast majority of my extended family, whom I love, is Republican. There isn't some great mystery to understanding their political motivations.