Sen. Elizabeth Warren formally announced her support for her 2020 presidential campaign's unionization on Thursday.
The big picture: Warren's campaign, which will be represented by the International Brotherhood of Electrical Workers (IBEW), is the fourth 2020 campaign to unionize — after Sen. Bernie Sanders, Rep. Eric Swalwell and former HUD Secretary Julián Castro, Politico reports.
Go deeper: Bernie Sanders' 2020 campaign staffers affirm union contract