Some of the nation’s largest labor unions representing nurses and public school teachers are spending heavily on leftist causes and candidates ahead of the 2026 elections.While their ostensive purpose is to negotiate wages, employee benefits, and workplace conditions, these unions continue to pour resources into critical races that could change the political makeup of Congress, as Democrats seek to retake the majority in November and progressive challengers, leaning on anti-establishment messaging, look to edge out more centrist opponents in primary upsets across the country.For instance, National Nurses United has donated significant sums this election cycle to candidates backed by the Working Families Party, a left-wing political party closely aligned with socialists such as Sen. Bernie Sanders (I-VT), Rep. Alexandria Ocasio-Cortez (D-NY), and New York City Mayor Zohran Mamdani. Sanders once referred to the WFP as “the closest thing there is to a political party that believes in my vision of democratic socialism.” NNU’s super PAC, National Nurses United for Patient Protection, directly gave the WFP and its San Francisco branch a combined $300,000, according to second-quarter election spending disclosures.