The religious left is struggling. Can the cause of economic justice help it rise again?

The religious left was never as powerful and cohesive as the religious right. But a new report based on many interviews with religious progressive leaders finds that the Obama era may have further weakened Democrats’ interest in the non-secular.

The report released Thursday by the Brookings Institution argues that religious progressives could be heading for a renaissance if they can focus on what some see as the civil rights issue of our time: economic justice.

The report, by the institute’s Governance Studies Program, is based on polling and interviews with many of the top players of Washington’s religious left. This includes John Carr, formerly of the U.S. Bishops Conference, evangelical writer Jim Wallis and Rabbi David Saperstein of the Reform Jewish movement.

It starkly lays out the challenges facing religious activists and voters who work for causes such as immigration reform and limiting budget cuts for the poor.

Their movement played a massive role in everything from the New Deal to ending slavery. Can it again be as impactful?

The report, co-written by Washington Post columnist E.J. Dionne Jr., finds that today’s religious progressives — like their predecessors — have not played a central role in organizing for Democrats the way religious conservatives do and did for the GOP. The success of Obama and the Democrats in 2008, it argues, “led not to a redoubling of interest on the progressive side religion, but quite the opposite. . . . Engagement with religion atrophied.” Many saw 2012 as widening the gap between secular and religious progressives because Obama and other Democrats had gained so much traction by pushing on socially liberal issues such as abortion and contraception — areas on which there is not unanimity among religious progressives.

The report lays out the key challenges for religious progressives:

● The numbers. Even as the religious conservative movement is failing to attract younger people, 56 percent of Republicans call themselves religious conservatives, while only 28 percent of Democrats call themselves religious progressives.

● Religious progressives are not homogenous and thus not as cohesive. Their views on abortion and gay marriage can vary, and their congregations are more politically diverse and thus harder to rally.

● Religious progressives are sometimes viewed suspiciously by their secular allies, in part because of skepticism about religion, but “[d]ifferences on social issues are almost always at the root of this secular mistrust,” the report says.

● Democrats are ambivalent about the role of religion in politics.

● Religious people are divided on whether the poor are helped more through the work of churches and other private charities or through government programs.

● The decline of the unions, a key partner for religious progressives.

● Growing divisions within the Catholic Church, the country’s largest source of money for grass-roots, faith-based organizing, over priorities and whether the church can work with liberal groups on something such as food stamps if they disagree on something such as gay marriage.

But amid the long list of problems, the report sees perhaps a bright future for the religious left.

One reason is demographics. A far bigger share of younger Americans call themselves religious progressives (34 percent of those ages 18 to 33) than religious conservatives (16 percent of the same group).

Another is a comparison to the Civil Rights movement, which the report says “interwove religious and civic themes” such as struggle, organizing and movement-building and was so successful because it was so ecumenical. We may be at such a moment, the report argues.

“[T]here’s a strong case that the current moment looks far more like the era leading up to civil rights activism than to the period that ushered in the religious right. Just as the civil rights movement spoke to a widespread desire in the nation to perfect the post-war social contract to include African-Americans, so do new social movements on behalf of greater equality and mobility speak to a broadly felt need for a new social contract. . . . Economic justice may prove to be the fertile ground of this era.”