Protesters demonstrate during a health-care rally at Thomas Paine Plaza on Feb. 25, in Philadelphia. (Mark Makela/Getty Images)

Seven years after the passage of the Affordable Care Act, Democrats seem finally to have secured a crucial element for its preservation: a robust grass-roots movement supporting it.

Pro-ACA protesters attended more than 100 rallies held Saturday across the country, organized by an activist group affiliated with Sen. Bernie Sanders (I-Vt.). That followed a congressional recess week during which GOP lawmakers were confronted by defenders of the health-care law in town hall meetings across the country. Numerous Democratic officeholders also held events touting the law’s successes.

The surge in activism comes as congressional Republicans prepare to take their next steps toward repealing the ACA, also known as Obamacare, and replacing it with what they say will be a more free-market-oriented system that is expected to cost the government less but cover fewer Americans.

The new mobilization represents a stark reversal of the recent political dynamics around health care. Until now, conservative activists have occupied the spotlight and relentlessly pushed Republicans to undo Obamacare, while Democrats and liberal groups largely stayed on the sidelines.

“There is a serious grass-roots element to this that previously the establishment Democrats didn’t really tap into,” said Julienne Gede Edwards, a 28-year-old Maryland attorney and colon cancer survivor, who attended a rally in Washington on Saturday and carried a sign calling on Republican lawmakers to lay out a health-care plan: “You’ve Had 7 Years — Let’s Hear It!”

People protest Trump administration policies that threaten the Affordable Care Act, Medicare and Medicaid, near the Wilshire Federal Building in Los Angeles. (David Mcnew/AFP/Getty Images)

Edwards added: “I don’t necessarily fault them for that. But I do think that now they are seeing that that energy is there, and that the grass-roots movement is working and is getting actual results.”

In Washington, several hundred protesters gathered Saturday afternoon on Capitol Hill, rallying in front of a deserted House office building before marching down Pennsylvania Avenue to the Trump International Hotel and on to the White House.

The crowd roared when Lance Christopher, a 29-year-old volunteer organizer, referred to President Trump and his chief strategist, Stephen K. Bannon, as “fascists.”

“If you think you can go to Starbucks, drink your lattes and life will go on as normal . . . you are sadly mistaken,” Christopher told the crowd. “These people are here, and they mean business, and we have to be as equally motivated.”

The event was one of more than 100 rallies planned for Saturday, many of them organized under the banner of Our Revolution — the grass-roots activist group that inherited staff and supporters from Sanders’s insurgent presidential campaign.

Had a pro-ACA rally been called several years ago, “I don’t think many people would have shown up,” Christopher said in an interview.

“I think there’s sort of a comfortability in the fact that your party occupies the White House, or even the Senate and House,” he said. And when the tea party movement pushed Republicans to repeal the law, “We sort of shunned it as a fringe movement,” he added.

People demonstrate for the Affordable Care Act and against Trump during the First Stand Rally in Newark, N.J. (Stephanie Keith/Reuters)

Now, he said, “We can’t underestimate anything anymore.”

As the protesters gathered outside the White House, Trump was inside having lunch with Wisconsin Gov. Scott Walker (R) and Florida Gov. Rick Scott (R), where they discussed “how best to solve the problems of Obamacare,” according to a Trump administration statement.

Both Scott and Walker represent states that refused to cooperate with the law by either setting up a state-run insurance exchange or accepting federal assistance to expand the Medicaid program in their states.

House legislation that will undo key Affordable Care Act provisions is expected to be introduced as soon as Monday, according to congressional aides. That legislation would ultimately undo the system of income-based tax subsidies and penalties at the center of the ACA as well as phase out the expansion of Medicaid, the federally funded health-care program for the poor that now covers 74 million Americans.

In its place, the Republican plan will probably offer an age-adjusted tax credit to help Americans purchase private insurance and boost funding for hospitals that serve many uninsured patients.

Sanders, who spent Saturday evening talking to Democrats in Kansas, said that the conservative state was getting a hard lesson in supply-side economics. Gov. Sam Brownback (R), who had signed a series of tax cuts, was among the Republican governors now asking that any reform of the ACA save the Medicaid expansion — something Republicans had sued to get rid of.

“There’ve been massive cutbacks in programs for working families,” Sanders said. “This is what Donald Trump is threatening to do for the whole country — he told working families he wouldn’t cut their Social Security or their health care, and we are going to expose him for that hypocrisy.”

Numerous GOP aides and lawmakers say that the goal of their system is to ensure universal access to insurance, not universal coverage. But Democrats say that the Republican plan could potentially cause millions to lose their coverage, and they have sought to highlight cases of sick Americans who might not have been able to access health care if not for the ACA. A consultant’s report shared at a National Governors Association conference this weekend, obtained Saturday by Vox, shows that recently floated GOP replacement proposals would indeed lead to a major decline in the number of insured Americans.

Some Republicans have characterized the protests and the town hall confrontations as the work of “paid protesters” and fringe groups, and they say they remain confident that voters want the ACA repealed and replaced. Others have promised to preserve the more popular elements of the law.

“The activist left is giving Democratic leaders fits as they search for answers after their failures in 2016,” said Jesse Hunt, a spokesman for the National Republican Congressional Committee. “A constellation of progressive groups are more than happy to play a hand in the process to try and promote the same far-left agenda that has been rejected by the American people in two consecutive elections.”

Polling continues to show an uptick in public support for the law, but it remains deeply divisive. The most recent Kaiser Health Tracking Poll showed the highest-ever level of favorability toward the ACA, 48 percent favorable versus 42 percent unfavorable, although the public remains almost evenly deadlocked on whether to repeal the law.

Over the weekend, the Democratic leaders of all 57 state and territorial parties converged in Atlanta to elect new officers. A billboard truck, paid for by the conservative American Action Network, circled the hotel and convention center where they were meeting, showing an image of House Minority Leader Nancy Pelosi (D-Calif.) and accusing the ACA of bringing about “higher costs, fewer choices, and canceled plans.”

But that ad, which is mirrored in mail being sent to House districts, makes no mention of a potential Republican replacement. “They’ve got nothing, zero,” said Brendan Dillon, the chairman of the Michigan Democratic Party.

Jane Kleeb, the chair of Nebraska’s Democratic Party, said that defending the ACA had been a non-starter in her conservative state. In 2012, Republicans helped scare Democratic Sen. Ben Nelson into retirement over his vote for the law. Two years later, they elected Sen. Ben Sasse (R-Neb.), who promised to repeal it.

“Nobody was talking about it — everybody’s head was in the sand, even progressives,” said Kleeb. “We didn’t feel like we got everything we wanted.”

Those doubts, she said, disappeared when Trump won and Republicans promised to gut the ACA. “All the farmers I work with are self-insured,” she said. “They need their insurance costs to stay down, and they need rural hospitals to stay open. That only happens if Obamacare stays in place.”

The recent uptick in engagement appears to be because of people like Nissen Ritter, a 57-year-old resident of Chevy Chase, Md., who does not personally benefit from major ACA programs but has family members who do — and who had not attended a political rally for years before Trump’s election.

Ritter said she had not felt compelled to march for health care beforehand: “I assumed that the people would want that. And so I felt like I didn’t need to say anything at the time. But now I’m sorry I didn’t.”

Asked whether she plans to attend more protests, she said, “One hundred percent.”

Weigel reported from Atlanta.