The first and perhaps most significant reason for skepticism is that there are far fewer religious liberals today than there were a generation ago. Nearly four in 10 (38 percent) liberals are religiously unaffiliated today, more than double the percentage of the 1990s, according to data from the General Social Survey. In part, the liberal mass migration away from religion was a reaction to the rise of the Christian right. Over the last couple decades, conservative Christians have effectively branded religious activism as primarily concerned with upholding a traditional vision of sexual morality and social norms. That conservative religious advocacy contributed to many liberals maintaining an abiding suspicion about the role that institutional religion plays in society and expressing considerable skepticism of organized religion generally. Only 30 percent of liberals report having a great deal or quite a lot of confidence in organized religion. Half say that religion’s impact on society is more harmful than helpful.

Another challenge confronting the progressive religious movement is the yawning generational divide in religious identity. Young liberals today are simply not that religious. Nearly half (49 percent) of liberals under 30 are religiously unaffiliated, according to the General Social Survey, which is more than the number who belong to all Christian denominations combined. Only 22 percent of liberal seniors are unaffiliated, while the overwhelming majority identify as religious. Your average left-leaning Christian is pushing 50. Coaxing young progressives to join a movement that would require them to reset their approach to religion is no small undertaking.