It has become a political and cultural flashpoint, drawing a clear divide between the "masked" and the "masked-nots." The disdain runs between the consciously unmasked president of the United States and his deliberately mask-donning Democratic rival, all the way on down to those crossing paths — and often crossing each other — in the cereal aisle of the grocery store.

"It's selfishness. Complete selfishness," says 57-year-old Tia Nagaki, of the barefaced shoppers she has encountered. A resident of Denver, where masks have been mandatory since May 5, Nagaki concedes she tends to give the side-eye to people like that. But just as often, she says, the sneers come at her, as happened recently when a maskless guy came too close at the market.

"He gave me a look, and then he started laughing at me like, 'Ha-ha, I don't care,' and making fun of me," she recalls. "We've made it very political. We've definitely politicized it."

Indeed, a recent Quinnipiac University poll shows overwhelming support among Democrats for mask wearing, but a little more than one-third of Republicans feel the same.

When Virginia Gov. Ralph Northam, a Democrat, announced a statewide mask mandate this week, he took pains to cast it as a more mild-mannered directive, with enforcement falling to health department officials, instead of police, and with no threat of jail time or fines for individual violators.

"This is a matter of public health," he said. "I'm not looking for people to get in trouble by not wearing a mask, but I am looking for people to please do the right thing. I am asking people to respect one another."

Still, Republicans immediately pounced, circulating pictures of the governor not wearing a mask in public just days before and blasting what they call "coercive" and "stifling burdens" on residents and businesses. It's the kind of politically charged resistance to mask mandates that has erupted around the nation and that has prompted officials to backpedal on mandates, reverse their position or get overridden by higher orders.

Several controversial incidents have helped fuel the backlash, including one in Philadelphia when police aggressively yanked a black man off a public bus, as cameras rolled, and another in New York City that started with a woman in a subway station being stopped by police for not having her mask on properly and that ended with her in handcuffs on the floor in front of her 5-year-old son. Police say she was arrested for disorderly conduct, not failing to wear a mask; she is reportedly planning to sue the NYPD.

Little wonder, police are loath to step into the fray.

"This is not a good look for us, and it puts law enforcement in an extremely untenable position," says Joe Gamaldi, president of the Houston Police Officers' Union. When a local mandate was ordered there, he urged officers to use their discretion and issue warnings, not citations or fines.

Having to enforce such a "draconian" mask mandate, Gamaldi says, would "erode trust that may be fragile with our black and brown communities" as well as with everyone else. Besides, he says, police are already stretched too thin and would better serve the public by focusing their limited resources elsewhere.

As it turned out, enforcement of the mandate became a moot point when an executive order from Texas Gov. Greg Abbott barred local penalties for violations.

But in jurisdictions that still have mandates, such as Virginia, businesses say it's unfair leaving it to them to step in to play "mask police," says Jodi Roth, director of government affairs for the Virginia Retail Federation. Restaurants and stores are more than willing to put up signs directing customers to wear masks, she says, but many refuse to be the ones to enforce compliance.

It's unreasonable, she says, to ask employees who've signed up to be cashiers or servers, for example, to manage customers who become hostile, abusive or even violent. Many have seen incidents themselves when asking people to wear masks. Others have just read about violence that has erupted elsewhere, including at a Waffle House in Aurora, Colo., where a cook was shot after telling a customer to wear a mask, and at a Family Dollar store in Flint, Mich., where a security guard was fatally shot following a confrontation over a mask.

The onus of enforcement, Roth says, should not be on businesses, which "have enough on their minds right now and are just trying to stay afloat."

"They don't want to have to turn anyone away right now," says Roth. "They're just trying to get back on their feet and make customers happy." It should be left up to businesses to voluntarily impose stricter restrictions, she says.

Lindsay Wiley, an American University Washington College of Law professor who specializes in public health law and ethics, tends to agree. Based on past experience ranging from HIV prevention to vaccines, she says, heavy-handed mandates can often backfire.

That may be especially true in this case, given how President Trump has been spurning masks and how the Centers for Disease Control and Prevention flip-flopped on the matter, first imploring people not to wear masks before encouraging their use.

"It can actually cause people who are skeptical of wearing masks to double down," Wiley says, and "reinforce what they perceive to be a positive association with refusing to wear a mask ... that they love freedom, that they're smart and skeptical of public health recommendations," all while bolstering the view that wearing a mask is a sign of weakness.

Heavy-handed mask mandates only "pour gasoline on the problem," agrees attorney Jeff Childers, who has brought a legal challenge to a mask mandate in Alachua County, Fla., arguing it's unconstitutional.

"It's not an objection to wearing a mask. It's an objection to being coerced to wear a mask," Childers says, adding that both he and his client recognize the health benefits and choose to wear a mask themselves. "I don't want to get too flag wavy on this," he says. "But isn't that really the foundation of our democracy, that we are a country of people who govern ourselves?"

But public health and elected officials continue to push back, trying to prevent the politicization of basic health precautions.

Mark Sexton, communications director for Alachua County, has posted more than 50 peer-reviewed articles about the benefits of wearing masks, in hopes of persuading residents to comply.

"Under a state of emergency, when people's lives are in danger, our board feels like putting a mask on for a few minutes when you run into the grocery store is not too much to ask," he says, comparing it to being required to put on headlights while driving at night. "It's a reasonable thing," he says.

And with the CDC recommending it, as well as Dr. Anthony Fauci, a top infectious disease expert and member of the White House's coronavirus task force, Sexton says, "it's common sense."

And, common decency, as Denver Mayor Michael Hancock puts it.

"So many people want to politicize this," he says. "But people are dying from this virus, and we need to do everything we can, regardless of party affiliation or ideological leanings, to protect them.

Recently, Hancock says, he drove 4 miles from home to pick up something at Home Depot. When he got there, he realized he had forgotten his mask, so he promptly drove back home to get it, before returning to enter the store.

"When I put on my mask, I'm doing it to protect them and to show compassion for my neighbor," he says. "And I hope they will do the same for me."

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