Bernie Sanders got his second major national union endorsement this week. The American Postal Workers Union announced it was backing the Vermont senator in his Democratic presidential campaign. The APWU represents more than 200,000 current and retired postal workers, and joins National Nurses United, which endorsed Sanders in August.

"Sen. Bernie Sanders stands above all others as a true champion of postal workers and other workers throughout the country," APWU President Mark Dimondstein said in a statement. "He doesn't just talk the talk. He walks the walk." "He is a fierce advocate of postal reform to address the cause of the USPS financial crisis and an outspoken opponent of USPS policy that degrades mail service," Dimondstein added, saying Sanders had fought the closure of post offices.

The APWU endorsement makes particular sense since Sanders has been a strong advocate for expanding the Postal Service’s offerings to include things like banking, strengthening rather than weakening the institution while offering needed services for unbanked and underbanked Americans.

Sanders, however, continues to lag behind Hillary Clinton in union endorsements. Clinton has the endorsements of the American Federation of State, County and Municipal Employees (AFSCME); the National Education Association (NEA); the American Federation of Teachers (AFT); the Operative Plasterers’ and Cement Masons’ International Association (OPCMIA); the Union of Painters & Allied Trades (IUPAT); United Brotherhood of Carpenters and Joiners of America (UBC); United Union of Roofers, Waterproofers and Allied Workers; the International Association of Machinists and Aerospace Workers (IAMAW); the International Union of Bricklayers and Allied Craftworkers (BAC); and the United Association of Journeymen and Apprentices of the Plumbing and Pipefitting Industry (UA).