Here’s a taste of McClay’s argument:
The loss of its morally and socially conservative but politically progressive Catholics has been a calamity, then, for the Democratic Party, and has seriously undermined its claim to be the vehicle of an effective and humane progressive politics. It is often argued that the socially conservative positions of Republicans are at odds with their support for unregulated capitalism, which serves as a ceaseless engine of social disruption, and a force perpetuating social inequality. But anyone putting forward that argument has to be willing to face up to an equally serious problem on the other side—that the extreme individualism presumed by so many of the current Democratic social policies, with their disdain for tradition and their obsession with liberatory rights-talk and atomistic privacy, is at odds with any sustained effort to foster notions of mutuality, accountability, community, and social responsibility.
Christopher Lasch argued that one of the chief errors of the postwar left was its choice of cultural radicalism, which succeeded, over serious political and economic reform, which failed completely. I think he was right about that, and the loss of the socially and morally conservative Catholics, who were—in a sense—very much like the socially and morally conservative Protestants that John Dewey described, is one of the chief casualties of that error. Both groups had a religiously derived vision of the human person, a vision that is fruitfully at odds with our American liberal individualism, and that could yet enrich a progressive politics that concentrated on the right issues, and once again respected their moral outlook. Both are still available for that purpose, if progressives can to find a way back to them. And if they want to.