Last weekend, nearly four hundred Teamsters from across the country gathered in Chicago for the forty-sixth annual Teamsters for a Democratic Union (TDU) convention. Members filed into the Crowne Plaza Chicago West Loop, a unionized hotel near the city’s O’Hare International Airport, sporting shirts and jackets with the International Brotherhood of Teamsters’ (IBT) distinctive double-horse insignia. With this year’s official Teamsters convention hosted online, the enthusiasm at the in-person TDU convention was palpable.

When they got down to business, it was to discuss rank-and-file organizing within the IBT just ahead of a November election that will determine new international union leadership. The agenda included workshops and conversations about the direction of the union, the election of TDU-backed candidates to office, the activation of members, and the existential threat posed by Amazon.

Over the years, TDU, a reform caucus of just a few thousand members, has had an outsized influence on the IBT, which represents 1.4 million union members across sectors including logistics, health care, construction, transportation, and communications. “We don’t call ourselves a caucus. We call ourselves a rank-and-file movement,” TDU national organizer Ken Paff told Jacobin.