(CNN) With the future of Obamacare in doubt, leading progressive grassroots groups are turning their eyes west, where California Democrats are pushing a new bill that would create a statewide single-payer health care system.

The shifting focus is at once a concession to Republican dominance on Capitol Hill and a mark of frustration, as activists continue to clash with establishment Democrats they view as unwilling or unable to craft a compelling alternative to President Donald Trump's agenda.

In California, progressives face a much more welcoming political environment. Trump is deeply unpopular there, and state Democrats are on the front foot, controlling both chambers of the state legislature and the governor's mansion.

"There's not many places where you can say to people, 'If we do this work, change can occur,' rather than, 'If we do this work, it will lead to change one day,'" Our Revolution board chair Larry Cohen told CNN, explaining why the organization, spun off from Sen. Bernie Sanders primary campaign, chose the Golden State for its most robust outlay since Election Day.

The western front

California legislators passed a single-payer bill in 2006, but Republican Gov. Arnold Schwarzenegger vetoed it. Similar efforts to create a single-payer system, in which the state, rather than private insurers, pays for health care, have stalled out at earlier stages. Those efforts, however, did not have the emerging Sanders operation -- with an estimated 300,000 supporters in California alone -- working as an engine room dedicated to driving popular support.

The current political leadership is expected to be more welcoming this time around. Gov. Jerry Brown is a Democrat and Lt. Gov. Gavin Newsom, one of the leading candidates to succeed Brown after he is termed out next year, recently said he planned to introduce his own universal health care program.

Organizers also point to the fight over Obamacare, and the specter of an overhaul authored by Trump and House Speaker Paul Ryan, as a potentially powerful motivator.

Never lose sight of the fact that our ultimate goal is not just playing defense. Our goal is a Medicare-for-all, single payer system. — Bernie Sanders (@SenSanders) March 12, 2017

Our Revolution, still better known as the storehouse for Sanders's coveted email list , sees the California fight as a chance to lay down a historical marker.

"It's a real test of whether we can be more than an email machine," Cohen said. "Not just people signing up for things online, but instead actually building a political organization. That's what it's always been about. I don't spend this kind of time as a volunteer and board chair to generate more emails."

Those efforts could be bolstered with the passage in Washington of the Republicans' American Health Care Act. The bill as currently composed would limit federal support for Medicaid by placing a cap on funding per enrollee. That would contribute to what the Congressional Budget Office predicts will be a surge in the ranks of the uninsured and, in an ironic turn, potentially provide new political momentum for single-payer advocates.

"The Republican proposal has put oxygen in the room for progressives to go on offense with real solutions that provide health care to everyone, increase quality, and reduce costs -- like Medicare for all or a public option offered to every American," Stephanie Taylor, co-founder of the Progressive Change Campaign Committee, said in an email.

"If Democrats learned the right lesson from 2016, they won't just depend on a negative message but instead pivot to bold inspiring ideas like Medicare for all," she added.

An unlikely opportunity

State Sen. Ricardo Lara, who co-authored and introduced the California bill in February, described it as a local necessity with the potential for creating a road map for other states. Hillary Clinton's defeat last year has accelerated the process, he added.

"There's no doubt that Trump's election and what Republicans are doing to dismantle health care has really given us an opportunity to have an honest dialogue about how we get to health for all," Lara said. "I don't think we would have had the same opportunity if Clinton would have won. Then again, we also wouldn't be in a place where we're going to lose billions of (Medicaid) dollars for California."

Lara views the health care fight as one piece of a broader play to turn back the Trump agenda -- first with grassroots resistance, then by actively shaping more attractive and inclusive policy.

"People in my district are genuinely scared -- scared that they are going to lose their health care, scared that their mom or dad might be deported," he said. "We have transgender children who are scared now about who they are and questioning that. Democrats in general, now, it's time for us not only to present alternatives, but be unequivocal and unapologetic about who we are. If we don't do that now, when? This is a moment that will define us as a party and we need to fight."

Proponents of single payer also make a pragmatic argument that the combination of Trump's unfavorable ratings and polling that shows growing support for federally guaranteed coverage has opened a window for immediate action. A recently published Pew report combining Gallup data going back to 2000 with a new survey found that 60% of Americans "say the government should be responsible for ensuring health care coverage for all."

Elected officials, though, are understandably wary of those numbers. Issue polling is a notoriously dubious indicator of how flesh-and-blood candidates will fare at the ballot box. Still, the upward trajectory is encouraging to activists and growing political organizations like the Democratic Socialists of America.

"Our longstanding positions on health care issues, such as supporting single payer and reproductive rights, are extremely important to new DSA members, including many young people that Bernie Sanders presidential campaign inspired to embrace democratic socialism," the group's deputy director, David Duhalde, said in an email.

'A new day in politics'

Turning to California, Duhalde touted his group's work canvassing in support of Lara's legislation, saying more than 200 people had volunteered to help push the bill.

RoseAnn DeMoro, the executive director of National Nurses United, an early union backer of the Sanders campaign and growing power base in progressive politics, said DSA's recent spike in membership underlined growing dissatisfaction with the Democratic establishment.

"It's a new day in politics," she said. "There is a dynamic base of people who are demanding health care. Demanding. It's not discretionary -- they want it, they need it, they are fighting for it. We've always got an extremely mobilized base from the Sanders movement. And they are determined to take legislators out who don't support basic issues."

National Nurses United, which plans to take a lead role in shaping the California bill and mobilizing supporters, is deeply entrenched in the state and expects Lt. Gov. Newsom, the 2018 gubernatorial candidate with his own single-payer plans, to be an ally going forward.

The long game

The national health debate remains mostly focused on repealing Obamacare, but there are signs that if Republican efforts fail, progressives could find new and strange bedfellows.

In the aftermath of a CBO report showing the Republican bill would, in comparison to Obamacare, nearly double the number of uninsured Americans, Newsmax Media CEO Chris Ruddy, a friend and supporter of Trump, published an essay calling for the White House to scrap the current plan and set a path toward "universal coverage."

The details of Ruddy's ad-libbed argument were perhaps less important than his willingness to write it. For progressives, the absence of a consensus on the right has breathed new life into long-stewing plans to pursue their own overhaul plans.

It was only in the mid 20th century, Our Revolution's Larry Cohen noted, that Canada began on a path he hopes Americans will follow.

"Obviously, the US is 10 times bigger," Cohen said. "But I think that we need to model this to take away the fear. And there's no place better than California to do it."