ASSOCIATED PRESS/Meg Kinnard Sen. Bernie Sanders addresses a rally in North Charleston, South Carolina, on Thursday. Alumni of his 2016 bid launched the movement to unionize Democratic campaigns.

Sen. Bernie Sanders’ presidential campaign has become the first major party presidential campaign to unionize. The campaign announced Friday that it had voluntarily recognized a bargaining unit organized with the United Food and Commercial Workers.

The news comes amid a budding movement to organize campaign workers in the notoriously tough working environment that is the campaign trail. The 2018 midterm elections saw the first congressional campaigns and party committees to have unionized workforces.

The group leading the charge, the Campaign Workers Guild, has organized 24 political campaigns since its 2018 launch ― although it was not the guild that succeeded in unionizing Sanders’ campaign.

“Sanders is the most pro-union candidate in the field, he’ll be the most pro-union president in the White House, and we’re honored that his campaign will be the first [major presidential campaign] to have a unionized workforce,” said Faiz Shakir, Sanders’ campaign manager.

Democrat Julián Castro, the former secretary of housing and urban development who is also running for president, promised earlier this year that he would recognize a bargaining unit if his staffers organized. Other Democratic contenders have been mostly silent, with none but Castro saying they would support a union when McClatchy polled candidates and likely candidates in late January.

Veterans of Sanders’ first presidential run in 2016 formed the Campaign Workers Guild in October 2017 with the goal of improving working conditions and forcing progressive candidates to practice the pro-union rhetoric that they preach. The guild ratified its first contract with then-Wisconsin congressional candidate Randy Bryce, who was himself a union ironworker, in February 2018.

Other prominent Democrats whose campaign staffs unionized in 2018 include Rep. Pramila Jayapal (D-Wash.), Rep. Deb Haaland (D-N.M.), Vermont gubernatorial candidate Christine Hallquist (D), and New York gubernatorial candidate Cynthia Nixon.

Sanders’ campaign staffers will become members of the UFCW’s Local 400, which represents 35,000 workers in Washington, D.C., Maryland, Virginia and several other states. The union has traditionally represented food and retail workers, but also represents employees of Solidarity Strategies, the consulting firm of Chuck Rocha, a senior adviser to Sanders’ 2020 and 2016 presidential bids.

In a joint statement with the UFCW, Local 400 said it had reached a neutrality agreement with the Sanders campaign on Feb. 26, ensuring that campaign management would not attempt to influence the outcome of the organizing effort and would immediately recognize the union when it had collected a majority of signed cards from employees selecting the union as their bargaining representative.

“We are so proud to join Local 400 alongside our union brothers and sisters in the struggle for security, justice and dignity,” said Christian Bowe, a digital communications staffer on Sanders’ campaign.

The leadership of the Campaign Workers Guild also released a statement on Friday expressing objections to the campaign management’s handling of the unionization process. The guild accused the campaign of ignoring requests for a union neutrality agreement with it over the course of nearly two months.

“While we wish our union had been given an opportunity to represent these workers, we fully support Bernie 2020 workers and are excited that campaign workers have succeeded in changing the status quo,” the guild said in the statement.

Campaign unions acknowledge that elections require workers to put in long hours. Their contracts have typically not sought to force candidates to abide by a normal 40-hour workweek, but instead secured higher pay, health care and retirement benefits, paid sick leave, paid personal time off and due process when a worker is fired.

The hierarchical leadership and pressure of campaigns can also breed impunity for sexual harassment perpetrated by managers or other members of campaign staff against their fellow employees. Several women who worked on Sanders’ 2016 campaign subsequently complained that the campaign did not adequately respond to the harassment they experienced on the campaign trail.

In an effort to improve, Sanders implemented mandatory harassment training for all campaign workers in his 2018 Senate re-election bid and hired a law firm to serve as an independent body where people can bring their harassment complaints without fear of retaliation.

A labor union can also serve to advocate for employees who have experienced harassment by pushing their case with management.

This story has been updated with more detail about the formation of the Sanders campaign staffers’ union and with comment from the Campaign Workers Guild.