Bernie Sanders’s bid for the Democratic nomination, his socialist self-identification, and his call for a “political revolution” in the United States has stirred up considerable discussion on the Left. That discussion has resurrected the perennial question of whether or not progressive forces should work within the Democratic Party or build an independent third-party alternative.

Since at least the New Deal, trade unions and the Democratic Party have stood at the center of working-class politics in the United States. As a result, both insider and third-party strategies propose to reconfigure the relationship between these two representative bodies: either increasing labor’s voice within the Democrats or breaking away and building a new party geared solely to workers’ interests.

The strategic alternatives boil down to one simple question: how do we build a genuine labor party capable of putting socialism on the agenda?