Labor Day, dedicated to honoring the American labor movement, has been a federal holiday since 1894.  While union membership has been declining in recent decades, there is a group of workers with growing interest in unionizing: campaign workers.

Traditionally – almost infamously –  campaign staffers work extreme hours for low pay. This is starting to change: Several of the 2020 presidential candidates have negotiated union contracts with their campaign staff. These negotiations include setting provisions for wages, benefits, hours, and vacation time.

Good news, especially at a time when women are making up a significant portion of the presidential candidates’ campaign staff. A Politico report shows that women consist of 60% of the senior leadership on the female candidates’ campaign staffs, and 54% of the top three male candidates’ senior leadership, a significant increase over previous years. By the way: research shows that gender diverse campaign staffs are more effective.

Unions have one more potential benefit: they may help protect women working on the campaigns. Meg Reilly, president of the Campaign Workers Guild, believes that unions are particularly important for women as they put in place protections for women that face sexual harassment while working on the campaign trail. With 81% of voters seeing sexual harassment in the workplace as a serious problem and candidates taking steps to prevent sexual harassment in their campaigns, supporting unionization of their campaign workers may be a way for candidates to show their support for the #MeToo movement.

In honor of Labor Day, here’s which candidates that have agreed to unionize their campaigns:

Senator Elizabeth Warren:

Elizabeth Warrens’ campaign staff is represented by the International Brotherhood of Electrical Workers.

Senator Bernie Sanders:

Bernie Sanders’ campaign staff is represented by United Food and Commercial Workers Local 400.

Senator Cory Booker:

Cory Booker’s campaign staff is represented by Teamsters Local 238.

Former Housing Secretary Julián Castro:

Julián Castro’s campaign staff is represented by the Campaign Workers Guild.