Interesting question.  The US is home to some of the largest social movements in the Western World, yet the US is also the farthest behind in terms of actual gains for the working class, women, and minorities.  How does this work?  Vincent Navarro describes the situation in the US and proposes that one of the key concepts missing from the American polity is a party, or even a politic that can bring people of the lower classes together to bargain for their interests collectively.  In other words, there is no real socialist option or ideological umbrella to foment behind in the political arena.  Most certainly there are groups and popular movements, each with individual muscle, but more strikingly evident, a lack of sinew and connective tissue to bind these various groups together in the polity.

This situation in which the progressive forces in the US are atomized is no mere accident.  The ruling classes have made it their project to remove socialist language and though from political discourse precisely because of how powerful class consciousness and solidarity are.  The success of the ruling classes venture is evident and brought to light by Navarro:

Moreover, the American business and conservative class, aware that the division of victims favors the victimizer, supports such division, hindering and impeding the transversality of such movements and showing great hostility toward the socialist project, which uses the concept of social class as the starting point of such transversality. This project—the alliance of the popular classes against the ruling class—is the most feared, since transversality would allow a union of actions that would weaken the ruling classes’ ability to exploit the rest of society. When the 1984 presidential candidate Jesse Jackson (whom I had the honor to advise) presented himself as the candidate of the black minorities, the New York Times (the voice of the political and media establishment) wrote an extremely laudatory editorial. Four years later in 1988, when he presented himself as the working-class candidate in the Rainbow Coalition, which united all races and genders of the working class, the same newspaper wrote an editorial accusing him of “wanting to destroy the USA.” When, in the last primaries of 1988, journalists asked Jesse Jackson how he was going to win the vote of the white worker from Baltimore (an industrial city), he answered: “by making him see that he has more in common with the black worker, for being workers, than with the owner and manager of the company, for being white.” Jesse Jackson won the primary of the Democratic Party in Baltimore and almost won nationwide, despite the enormous opposition and hostility of the political and media establishments, including the apparatus of the Democratic Party. More recently, during the 2016 U.S. presidential elections, the socialist candidate Bernie Sanders emphasized the need to unite the “working American families” in a coalition that cuts across identity differences. He almost won the primaries, despite the opposition of the Democratic Party apparatus (including the opposition of the feminist movement NOW, which supported Hilary Clinton as its favored candidate).

Following the rise of so-called populism based on identity causes, it is important to underline this point. Promoting populism with its great diversity of anti-establishment movements, celebrating such diversity without any criteria in terms of transversality that can unite such movements, is to reproduce what has happened in the United States, the country of social movements (except for the socialist movement) where the left (and women and the minorities) is enormously weak.