The liberal focus on using coalition politics to get to 50.1 percent in presidential elections has led to historic losses at the state and local levels, with Republicans now standing in total control in 26 states (as against six for the Democrats) and having shifted the House and Senate right. In “The Once and Future Liberal: After Identity Politics,” author Mark Lilla suggests a unifying theme that picks up on Bernie Sanders’ central insight — that the big political question today is what you earn (not enough) rather than who you are (black, gay, female, Muslim, Latino or, ideally, all five).

The Democrats are all about divide-and-conquer tactics when what they need is a vision of our shared destiny and the things we all hold in common as Americans. “Liberals have become America’s ideological third party, lagging behind self-declared independents and conservatives,” writes Lilla, a Columbia humanities professor and committed liberal who believes the single most important issue is on-demand access to abortion for women.