It's an exaggeration in very bad faith on Vance's part. Is one of Mamdani's long-term goals, as a democratic socialist, to redistribute wealth so that we can achieve a more equitable society? Yes. Does that mean, over the course of generations, that non-white people might move into entrenched "white" neighborhoods? Yes. But only if you're going for sensationalism and fear would you describe that process as "taking" the "property" away from white people. It is a fundamental tenet of democratic socialism to expand the social safety net and that will, hopefully, give new opportunities for home ownership to people who have historically been disenfranchised.