Forest for the trees, here. Oops, I'm sorry, the guy isn't 1600 miles away, maybe it's 1800 miles, maybe it's only 1500, but what it is is a whole fucking long way to go to kill people because you don't like what they look like.
This isn't about Arizonans, or whatever you call people who live in Arizona, it's about a guy who lives a long way from Atlanta who wants to kill black people enough to want to go that far to do it. It certainly isn't unique to that county, or that city in that county, and it is pretty fucked up.
It is well known that a number of states sow division in the populace of their enemies to weaken them. Does polarizing hot button issues do that? History says it does.
Does Palestine matter to them? No. Does polarizing the populace of the enemy matter to them? Yes. Are either of the organizations linked above tools of states that would like to harm America? I don't know. Could they, or similar organizations be used that way? Sure.