Commentary magazine: Matthew Continetti on "What Nathan Glazer Can Teach Joe Biden." An excerpt:Biden is facing the dual challenges of a resurgent radicalism and an emergent population that is disconnected from the core ideas and practices of the United States of America. Not only will he have to understand the contours of public opinion and address the institutional failures that lie behind it. He also will have to formulate convincing justifications for the individual and group inequalities that accompany the development of free societies. In short, he will have to remember the answers.