In recent decades, alternative organizations and movements -'quasi-unions'- have emerged to fill gaps in the US system of representation caused by union decline. We examine the record of quasi-unions and find that although they have sometimes helped workers who lack other means of representation, they have significant limitations and are unlikely to replace unions as the primary means of representation. But networks, consisting of sets of diverse actors including unions and quasi-unions, are more promising. They have already shown power in specific campaigns, but they have yet to do so for more sustained strategies. By looking at analogous cases, we identify institutional bases for sustained networks, including shared information platforms,...