Fed up with anti-maskers, mask advocates are demanding mandates, fines — and common courtesy.

So far, van Vonno has kept those feelings mostly to herself. But at a recent museum board meeting in Melbourne, Fla., she was one of only two people out of 10 wearing a mask. She said nothing at the time, but she wishes she had.

“I thought about it,” she said, “and I need to bring it up.”

In a country stumbling to control a rampant and deadly virus, masks are effective and popular weapons. Three-quarters of Americans favor requiring people to wear face coverings in public to stop the spread of the novel coronavirus, including 89 percent of Democrats and 58 percent of Republicans, according to an Associated Press-NORC Center for Public Affairs Research poll in July.

Now, with the nation reeling from more than 5 million infections and nearly 170,000 virus-related deaths, a rising sense of outrage is leading this silent majority to push back against the smaller but louder anti-mask contingent.

Instead of flashy protests and confrontations, however, mask supporters are expressing their exasperation in quieter ways, writing letters to local newspapers, posting on social media, patronizing businesses identified as mask-enforcers on dedicated Facebook groups and urging state and local officials to mandate mask-wearing in public.

So far, 34 states and the District have adopted mask requirements. Now, mask advocates want police to enforce those orders, a move some police chiefs have said they are reluctant to make. They are seeking legal protection for retail workers put in the awkward position of enforcing mask rules. And they are lobbying for a coordinated federal mask policy.

“People who are for masks are riled up,” said Henry Karp, 70, a retired rabbi in Davenport, Iowa, with “one fully operational lung.” But, Karp said, “you’re not going to see us gathering on the steps of state capitols with semiautomatic weapons for the same reason we’re wearing masks — we want to stay safe.”

Politicians, most of them Democrats, have adopted increasingly sharp rhetoric to push for compliance with mask orders and recommendations. Masks were highly visible throughout the first night of the Democratic National Convention. The party showcased masked health workers risking all to save victims of covid-19, presented multiple images of Joe Biden wearing a mask, and topped off the evening with Michelle Obama’s lament that the nation’s children “see people shouting in grocery stores, unwilling to wear a mask to keep us all safe.”

Biden has said that, if elected, he would use his executive power to mandate mask-wearing nationally. Until then, Biden put the onus on the nation’s governors, calling on them last week to require mask-wearing in public for at least the next three months.

North Carolina Gov. Roy Cooper (D), who issued a mask order in June, has said “the refusal to wear a mask is selfish” and defies “basic decency and common sense.” He added, “Either wear one or don’t go in the store.”

And Virginia congresswoman Jennifer Wexton (D) tweeted, “Wear a damn mask,” after mask-skeptic Rep. Louie Gohmert (R-Texas) last month tested positive for the virus. House Speaker Nancy Pelosi (D-Calif.) subsequently required masks on the House floor.

Without a national policy on masks, many businesses have set their own rules. Delta Air Lines earlier this month put at least 130 people on a no-fly list because they refused to wear masks on the airline’s flights. Alaska Airlines also announced it would ban passengers who refused to cover their faces.

“We’re enforcing it and we’ve been very public,” Delta’s chief executive, Ed Bastian, said at a Washington Post Live event. “We’re going to make certain that we enforce it even if the federal government doesn’t give us the backup.”

The battle over masks, like earlier faceoffs over requiring seat belt use in cars or banning smoking in public places, pits defenders of science against defenders of personal liberty — a classic American faceoff of the collective good against individual rights. But unlike those earlier debates, the mask battle has become politicized, making masks one more weapon in a national tussle over values and factional power.

Cheap and easy to make, masks are an unusually simple protective tool in a pernicious pandemic. This spring, a scientific consensus emerged that masks provide real protection, replacing earlier doubts expressed by the World Health Organization, Surgeon General Jerome M. Adams and other U.S. officials.

But masks remain inherently troubling: They hide who we are. Throughout history, racists, political extremists and criminals have hidden behind KKK hoods, balaclavas and ski masks. In many places, like banks and airports, masks are — or were — discouraged or even illegal. Some states have now carved out exceptions for disease prevention.

President Trump has sent mixed messages on masks, repeatedly expressing his distaste for them even while occasionally acknowledging that they protect against viral spread. Last month, Trump tweeted that wearing a mask is “patriotic,” and he has worn one in public on occasion.

But many of Trump’s fans have latched onto his objections. While 94 percent of Democrats said in a July Gallup poll that they’d worn a mask “always” or “very often” when outside their homes, only 46 percent of Republicans said the same.

In addition to partisan politics, resistance to masks is driven by the American tradition of individualism, said James Keena, a novelist of dystopian science fiction whose latest book, “2084: American Apocalypse,” depicts a country destabilized by government overreach.

“If I were in a crowded Walmart with a lot of elderly people who might be at risk, yeah, why not, I’ll put on a mask,” Keena said. “But a lot of people have concluded this virus really isn’t such a big deal, and yet they’ve seen government suspend freedom of movement and freedom of assembly. They’ve learned mistrust or even anger through this crisis.”

A flood of news reports and viral videos starring angry people who refuse to wear masks confirms that impression. Mask opponents have staged armed demonstrations at state capitols, packed local government meetings and spread anti-mask memes on social media, often casting face coverings as “muzzles.”

In New York City, a man punched a 62-year-old bus driver in the face after the driver stopped him from boarding without a mask. In Los Angeles, two taco stands shut down after customers cursed, shouted and threw drinks at restaurant workers who politely asked them to cover their faces. And in Tucson, a man had to be physically carried out of a supermarket by his son after he threatened to “beat that f—— mask off” the face of another man.

Mask advocates are starting to respond with a quieter rage. Frank DeRiso is a union president in Upstate New York, where he says nearly everyone wears masks in stores. But on a recent visit to Myrtle Beach, S.C., he was dismayed to find hardly anyone covering their faces. “These people are jeopardizing my life,” he recalled thinking.

DeRiso, who is 66 and has a lung disease, didn’t say anything at the time for fear of sparking an angry confrontation. But “I couldn’t wait to get out of there,” he said.

Back home in Buffalo, DeRiso’s union is taking action, filing a grievance against a local supermarket chain that gives out free masks to customers along with leaflets explaining New York’s order to cover faces. That’s not enough, DeRiso said; the stores should also enforce the order by barring maskless customers from entering.

“They need to meet them at the door and say they can’t come in,” he said. “Tell them we’ll shop for you if you won’t wear a mask. People are getting sick and dying. It’s time to enforce this.”

In Greensboro, N.C., Charlie Hargett has become a one-man crusader for face covering, equipping workers at his construction firm with protective gear and creating a website, covidfree.com, that preaches the power of masks. The site offers businesses a “Covid-Free” certificate to post in their windows if they agree to require masks and take other precautions.

When a manager at his local Home Depot told him they request that people wear masks, but do not require it, Hargett said, “That’s not good enough.” He filed a complaint with the Better Business Bureau. A couple of weeks later, Home Depot announced it would require all customers to wear masks in its stores.

“Most people want to avoid confrontation, and the ones not wearing masks are the people who want a confrontation,” Hargett said. “They don’t want to be told what to do, and they feel empowered because you’ve got an arrogant, stubborn, ignorant person running the country, refusing to wear a mask. And that sends a message.”

A former Trump supporter, Hargett said he is “ashamed to be a Republican,” and has no patience for people who claim masks rob them of their freedom.

“Nobody complains that their freedom’s being taken away because they have to wear pants. But that’s the law,” he said. “We need leadership on this. The only way you’ll ever get full participation is if police take action and enforce a mask mandate.”

That’s exactly what David Canepa wants to do. Canepa, who serves on the board of supervisors in northern California’s San Mateo County, said he has heard enough from science-deniers, especially in light of new evidence showing that masks appear to protect the wearer as well as people who might breathe in their exhalations.

“People need to rely on the science and not on their high school buddy who took science with them,” Canepa said. “I didn’t get into elective office to tell people what to do, but this is a health emergency, and we have a silent majority that’s doing the right thing. We’ve done the education, we’ve tried to work collaboratively. Now we need to enforce.”

Earlier this month, San Mateo’s board voted unanimously to fine anyone found in public places without a mask. Police, park rangers, building inspectors and other county workers will hand out both masks and summonses. Fines are $100 for a first offense and up to $500 for further transgressions.

“Small business owners don’t want to confront customers. I understand: We’ve all seen those ugly confrontations on YouTube,” Canepa said. “Now we’re giving them a way to say, ‘Hey, it’s the county making me do this. If I don’t enforce it, they’ll fine me.’”

Businesses and their employees have good reason to be wary of acting as mask enforcers. The most vehement mask opponents have occasionally turned violent.

In Lansing, Mich., when Sean Ruis entered a convenience store last month without a mask, a store employee asked him to cover his face. Ruis reacted angrily — and stabbed a 77-year-old customer. A sheriff’s deputy shot and killed Ruis outside his home a half-hour later.

More often, though, anti-maskers pose a more prosaic threat.

In Caldwell, Idaho, when the local health board voted last month simply to recommend — not require — masks in public, bare-faced residents packed a local courtroom and loudly booed all mention of masks, infection tracing and virus hot spots.

That same week, hospitals in the area reported that their intensive care units were at capacity, filled almost entirely by patients suffering from covid-19.

Emily Guskin contributed to this report.