Business unionism is out, social movement unionism is in: On this, North American union activists agree. They’re confident that, after decades of givebacks and setbacks, labor can finally turn itself around if it starts thinking more like an expansive movement and less like an agglomeration of hidebound institutions.

To a cynic’s ear, such declarations do not excite. They resemble a call to arms “full of sound and fury, signifying nothing.”

But while skepticism regarding the actual practice of social movement unionism is warranted, complete dismissal is not. Debates around labor revitalization strategies use this concept as shorthand for the best we might aspire to: a unionism that is militant, internally democratic, committed to social justice, attuned to class, and part of larger social and political mobilizations.