Trade unionists in the 1920s didn’t have much reason for optimism. Labor membership, which had shot upwards amid postwar unrest, crested and then plunged. Observers fretted that technological and cultural changes had rendered the labor movement obsolete and workers apathetic. “Our younger members, especially, have gone jazzy,” one union official lamented in the mid 1920s.

A decade later, strikes were blocking production across the country, and union density was skyrocketing.

After years of malaise in the labor movement, is a similar upsurge possible today?