I don’t think the EU and the US are very different. Then again, Texas isn’t exiting. (No disrespect, just pointing out the difference.) But divisions in the EU are very familiar to Americans and understandable for the exact same reason.
Asking a Californian to understand and relate to the issues of a Missourian deeply, and vice versa, is a little unfair to both and we’d all be so much happier if we were simply fine with that. People are different. The idea of the United States has been forcing it in a lot of unwilling minds for a long time, I think, and the consequential bitterness that really has no reason whatsoever to exist is unfortunate.