State Democrats’ three-day convention had a raucous start Friday, as liberal activists booed and heckled Democratic National Committee Chair Tom Perez after marching from the state Capitol to promote a universal heath care program.

The leader of the nurses’ union that opposed Perez’s recent election had just warned California Democrats that they would put up primary election challengers against lawmakers if they don’t support a bill to create public-funded, universal healthcare.

“They cannot be in denial anymore that this is a movement that can primary them,” RoseAnn DeMoro, executive director of the California Nurses Association, told hundreds of nurses and health care advocates gathered for a rally at the Capitol.

“Vote them out,” the crowd chanted back, referring to Democrats in the Legislature wavering on whether to support their cause.

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As California Democrats kicked off their weekend convention here with a cocktail reception featuring trays of scallion pancakes with Hoisin sauce and red grapes rolled in blue cheese and coated in pistachios, the throng advocating for a statewide publicly funded, universal health care system snaked down a staircase behind Perez, shouting down his calls for unity.

“This gathering kind of reminds me of Thanksgiving dinner at my house with my extended family,” Perez said, trying to lighten the mood.

As Perez launched into a riff about shared party values, California Democratic Party John Burton told activists he backed universal healthcare before many of them were born, in 1998. He jabbed at a protester: “Put your (expletive) sign down...We’re all for it.”

“We make sure that healthcare is a right for everyone,” Perez said. “And not a privilege for a few.”

The showdown over health care exposed deep rifts within the party that may have scabbed over, but have not healed, since last year’s primary fight between Hillary Clinton and Bernie Sanders, a favorite of the nurses union, which also backed Perez’s opponent in the chair’s race, Rep. Keith Ellison.

Sanders has called for a national single-payer system, and earlier this month called on Californians to adopt the model at a speech in Los Angeles.

DeMoro argued the Republican health care bill that passed the House has generated anger and fear among people from across the political spectrum, and many have turned their attention to the issue of health care because they fear losing coverage. Lawmakers have expressed skepticism over its projected steep cost.

“There’s been a seismic shift because of Donald Trump,” she said in an interview.

Perez, in his brief remarks to delegates, sought common ground over their shared anger toward Trump.

“We have a president .... I don’t know who it is, Putin, or Trump,” Perez said. ‘They’re in a bromance. This is really weird.”