But maybe his proposal is closer to political realism. The expert consensus holds that the way to bring down housing costs is to build more housing; and the best way to do that is to remove the regulatory barriers to a construction boom. When I interviewed Mamdani about his housing plans, however, he emphasized that although more building is necessary, it is not sufficient—or sufficiently fast. “We absolutely have to expedite the process by which we build new housing,” he told me. “But we can’t do that unless we also address people’s immediate needs.”