A nurses union that's long been a major booster of Sen. Bernie Sanders (I-Vt.) and his signature plan for single-payer health care urged political candidates Wednesday night to reject donations from a powerful coalition of insurance and pharmaceutical companies and hospitals that oppose Medicare For All.

National Nurses United called on candidates up and down the ballot — from the remaining presidential hopefuls to members of Congress to local city council members — to sign their "Patients Over Profits Pledge" and reject any donations from any members of the Partnership for America’s Health Care Future.

“We know that we need to fight back,” Jasmine Ruddy, the lead organizer for NNU’s Medicare for All campaign, told POLITICO. “It’s long overdue for us to take aim at the influence this Partnership has both with the public and in Washington.”