I wholeheartedly disagree with that. Alexandria, maybe. But Fairfax County is pretty large: it encompasses Annandale, Springfield, and Centreville. Springfield has a heavy latino population, and Centreville and Annandale have like a 25% Asian population. Annandale even has a section called "Little Korea" for pete's sake.

To be fair, though, Alexandria is not fair from Arlington, and about the only people who can afford to live in either of them these days are trust fund babies.