Is it no longer polite to ask someone about their cultural, ethnic, or immigration background in America?

Unlike my more ignorant neighbors, I like diversity and learning about different people. But these days, when someone is asked, “Where are you from?” it’s automatically assumed they’re fishing for a reason to consider them less of a human being (i.e. “You’re not a ‘real’ American.”)

If this has become a delicate topic, then what’s a more tactful way of asking about those parts of a person’s identity?