Photo has been used for illustrative purposes.

John Woolfolk, Tribune News Service

California’s Orange County health officer resigned last week after protests at her house over her mask mandate. Fresno, Riverside and San Bernardino counties softened theirs after push-back. President Donald Trump has famously shunned the coronavirus face covering. And Santa Clara County resisted mask orders for weeks before joining other Bay Area counties in requiring them.

Around the country, face masks — perhaps the most visible manifestation of the COVID-19 pandemic — have become a political football, inspiring debate and resistance even as studies emerge showing they can help corral the contagion.

So why are we at war over masks? Turns out, face coverings have been controversial in the US for more than a century, according to Robert A. Kahn, a professor and mask law expert at the University of St. Thomas law school in Minneapolis. When it comes to public health, he said, experience has shown a light touch is most effective in persuading Americans to wear them.

“I think that a lot of the public health experts and officials are very well-intentioned, but I think on some level they’re tone deaf,” Kahn said. “When you over-enforce something like mask-wearing, you risk backlash.”

On Friday, after weeks of protests and the Trump campaign building momentum for a slate of political rallies, the Centers for Disease Control and Prevention suggested organizers of large public gatherings that involve shouting, chanting and singing to “strongly encourage” people to don face masks.

“I think frankly this is an area where our public health messaging early on in the pandemic was not helpful,” said Dr. Kirsten Bibbins-Domingo, a professor of epidemiology and biostatistics at the University of California San Francisco. “It has created a lot of confusion. Public health requires public trust, and the situation we’re in now is trying to realign messages so we can be clear.”

The latest debates have erupted with coronavirus cases continuing to mount as the country eases restrictions on businesses and activities that have been shut down for months, and as more studies demonstrate the benefits of masks in reducing the virus’ spread.

A National Academy of Sciences study on mask wearing in New York, Italy and Wuhan, China, where the pandemic began, found mandated face coverings “significantly reduce the number of infections” and that other measures such as social distancing “are insufficient by themselves in protecting the public.”

“Basically, it said if we’re not sheltering and going to be out, face masking is the best thing we can do,” Bibbins-Domingo said.

As health officials began planning reopening, however, there was less agreement on whether to require or merely encourage mask-wearing in public. In mid-April, health officials in San Francisco, Alameda, Contra Costa, San Mateo, Sonoma and Marin counties made mask-wearing in most public settings a requirement for anyone over age 12, with violators potentially facing criminal prosecution.

Elsewhere, similar mask mandates have led to open rebellion. Fresno, San Bernardino and Riverside counties softened mask requirements after criticism. And Orange County Health Officer Dr. Nichole Quick resigned Monday night after protests outside her home over her order to wear masks in public. Her replacement immediately made it a recommendation.

The mask requirements have met more pushback in conservative-leaning areas, where many see the lockdown orders as an overreaction not worth the economic cost. Conservative leaders, President Trump included, have made a point of not wearing masks in public. Republicans even moved Trump’s speech to accept the party’s nomination to Florida over the no-mask stand. The visibility of masks has made them symbolic in the debate, Kahn said.

“For some of these people on the right, they’re viewing the mask as the blue version of the MAGA hat,” Kahn said, referring to Trump’s red Make America Great Again campaign hats.

Kahn said mask requirements were just as controversial in the US over a century ago during the so-called Spanish Flu pandemic in 1918.

“America has an individualistic culture” that is suspicious of mandates, Kahn said. And the stricter they are, the more people rebel. During the 1918 pandemic, an order in Tucson, Arizona, that many viewed as needlessly restrictive was defeated in a court challenge.

“What the Tucson experience shows is you have a risk of backlash when you have an all-reaching mask law that has no reasonable exemptions,” Kahn said. “It leads to angry people, and angry people aren’t going to wear mask out of spite.”