National Nurses United
Castillo has used her position as head of the nation’s largest nurses’ union to advocate for better protection for front-line workers and improved nurse staffing ratios, among other things. Most recently, she’s been critical of the Biden administration declaration that fully vaccinated people do not need to wear masks in most settings. Castillo argued that the guidance puts health workers at continued risk. The union has also been active in lobbying for stronger protections to guard against workplace violence.