" The forces at work in healthy party politics are centripetal; they encourage factions and interests to come together to work out common goals and strategies. They oblige everyone to think, or at least speak, about the common good. In movement politics, the forces are all centrifugal, encouraging splits into smaller and smaller factions obsessed with single issues and practicing rituals of ideological one-upmanship. So the New Left's legacy to liberalism was a double one. It spawned issue-based movements that helped to bring about progressive change in a number of areas, most notably the environment and human rights abroad. And it spawned identity-based social movements -- for affirmative action and diversity, feminism, gay liberation -- that have made this country a more tolerant, more just, and more inclusive place than it was fifty years ago.

What the New Left did not do was contribute to the unification of the Democratic Party and the development of a liberal vision of Americans' shared future. And as interest slowly shifted from issue-based ones, the focus of American liberalism also shifted from commonality to difference. And what replaced a broad political vision was a pseudo-political and distinctly American rhetoric of the feeling self and its struggle for recognition. Which turned out to be not all that different from Reagan's anti-political rhetoric of the producing self and its struggle for profit. Just less sentimental and more sanctimonious. "

― Mark Lilla , The Once and Future Liberal: After Identity Politics