Everyone's identity is complex, just as you say. And everyone's identity should be respected. Matter of fact, not respecting someone complex identity may be, itself, racist by people who don't understand that we are all complex creatures.
You've provided a primer on race, religion, and cultural identity. Thank you for that.
But the simplistic designations "non-Hispanic white" and "other racial and ethnic groups" that are used in this article can be used to draw conclusions about these two groups of people. and about how each group is treated.
Religion, as you say, is another matter, and Trump's executive order to ban Muslims from entering the country was an act against people who believe in a particular religion. I do wonder, however, whether Trump even understood he was acting against a religion rather than against a race.
And supporting white supremacists really cannot be viewed as anything other than supporting racism.