The day after Democrats in the California Senate passed a proposal for a universal health care system, RoseAnn DeMoro took to Twitter to call out those who voted against it.

Her tweet read: “23 CA senators stood up for guaranteed healthcare, 17 did not – some of whom are Dem. Check if your senator is here.” A list was included showing how each lawmaker voted on the bill.

Its passage marked an incremental victory for DeMoro, a liberal Democratic firebrand who, as head of the California Nurses Association, has spent decades pushing to overhaul the health care system. Most advocates don’t celebrate a win by publicly shaming the politicians who took the losing position. But DeMoro is hardly the typical advocate.

A union boss with a take-no-prisoners approach, DeMoro has a long history of rabble-rousing through civil disobedience and theatrical stunts. She has no use for the practical politics of compromise and consensus-building, preferring to strive for progressive ideals rather than find common ground.

Now, as Democrats across the nation struggle to rebuild following last year’s electoral losses, DeMoro is leading the effort to push California’s party further to the left.

RoseAnn DeMoro is closely aligned with Vermont Sen. Bernie Sanders.

RoseAnn DeMoro is closely aligned with Vermont Sen. Bernie Sanders.

“People are seeking an alternative vision for this country,” said DeMoro, whose union campaigned heavily last year for her longtime friend, Sen. Bernie Sanders of Vermont.

With Republicans in Washington vowing to repeal the Affordable Care Act and California Democrats in vocal opposition to President Donald Trump, DeMoro has seized the moment to push for a single-payer system – health care as a government-run service like public education, paid for with tax dollars and available to all. She’s made her union’s single-payer plan, which is moving through the Legislature as Senate Bill 562, a wedge issue for Democrats, threatening to campaign against those who don’t support it.

“This is my unification speech, which is a warning,” DeMoro told the crowd at last month’s California Democratic Party convention. “If you dismiss progressive values and reinforce the dynamic status quo, don’t assume the activists in California or around this country are going to stay with the Democratic Party.”

As she invigorates liberal “Berniecrats,” DeMoro is infuriating the party faithful. Eric Bauman, the new chairman of the state party (whom DeMoro did not support in his bid for the position), has excluded the video of her speech from the party’s YouTube channel and declined to be interviewed for this article. Even some Democrats within organized labor have grown weary of her combative style.

“When you’re the minority party nationally now, trying to divide your own party doesn’t make sense to me,” said Gale Kaufman, a Democratic political consultant who works for the state teachers union. “Bringing people closer together seems to be smarter.”

DeMoro, who is 69, grew up in St. Louis, married her high school sweetheart, then moved to Santa Barbara to study sociology. Working at a supermarket while raising two children, she became an organizer for the grocery workers union before going to work for the Teamsters. She joined the California Nurses Association 32 years ago, attracted to a position that would allow her to empower working-class women. She helped nurses get retirement benefits, pushed for laws to limit their patient load and more than quadrupled the size of the union, which now nears 95,000 members.

Her relationship with Sanders dates to at least the early 1980s, when she supported his campaign for mayor of Burlington with a $20 donation. At the time, DeMoro said, “that was a lot of money for me.”

Today, DeMoro earns more than $350,000 as executive director of the California Nurses Association and its umbrella, the National Nurses United. Her husband, Don DeMoro, recently retired after working for many years as the union’s director of research. The couple lives in Napa, and together drew nearly $700,000 in salary and benefits in 2014, according to the union’s most recent tax filings.

DeMoro has drawn inspiration from the civil-rights era song “It Isn’t Nice” as she’s made her union a hotbed of in-your-face activism. “It isn’t nice to block the doorway/It isn’t nice to go to jail/There are nicer ways to do it/But the nice ways always fail.”

In 2005, DeMoro led scores of protests against Republican Gov. Arnold Schwarzenegger as he tried to increase the ratio of patients to nurses in California hospitals (his effort failed). Five years later, her union followed GOP gubernatorial candidate Meg Whitman around the state with an actress dressed in a velvet cape who staged satirical portrayals of “Queen Meg” (Whitman lost).

RoseAnn DeMoro and her nurses' union were a thorn in former Gov. Arnold Schwarzenegger's side.

RoseAnn DeMoro and her nurses’ union were a thorn in former Gov. Arnold Schwarzenegger’s side.

DeMoro’s protests haven’t focused only on Republicans. In 2011, after nurses were arrested at Occupy protests in Chicago, DeMoro led her union to picket Democratic Mayor Rahm Emanuel. In 2006, DeMoro heckled then-Assembly Speaker Fabian Núñez, who was pushing a bill to expand health care, but not through a single-payer system. Núñez, a Democrat, remembers hosting a screening in Sacramento with filmmaker Michael Moore, a fan of the single-payer concept.

“RoseAnn and everybody was outside the premiere protesting me because they didn’t like my bill,” Núñez recalls. “Even Michael Moore was like, ‘I think it’s a good thing, you’re trying to change things.’ But RoseAnn was to the left of Michael Moore.”

Núñez praised DeMoro’s staunch defense of her values but said the approach is not effective: “It’s one thing to fight for what you believe in; it’s another thing to get something done.”

Last year, the California union spent $260,000 to support a ballot measure aimed at keeping a lid on drug prices, but it lost. The union’s national arm spent $4.8 million on Sanders’ losing presidential campaign. (Financially, they were outgunned.) And despite the nurses’ advocacy, single-payer bills in California have stalled or been vetoed half a dozen times since 2003, due in large part to their enormous cost.

This year, DeMoro insists, will be different. Trump’s election has changed the national narrative on health care, she says, making more Democrats open to the nurses’ vision for universal coverage.

“They have provided the momentum and the movement, which helps on something this large,” said Democratic state Sen. Toni Atkins of San Diego, an author of the single-payer bill, who said she hears constantly from activists who support it.

Some Democratic senators who voted against the bill said they want to focus on preserving Obamacare rather than advance a single-payer plan that in its current form lacks essential details – such as how to come up with more than $300 billion to pay for it. Sens. Richard Pan of Sacramento and Steve Glazer of Orinda said DeMoro’s threats don’t scare them.

For her part, DeMoro is hoping to retire soon. But she’s not making those plans just yet.

“I will go away if we get a single-payer system,” DeMoro said. “I promise.”