Viral videos of bloody skirmishes between right-wing activists and self-described anti-fascists have drawn national attention to Portland, Oregon — a city of storied political activism that has struggled to keep the peace at dueling rallies illustrating a microcosm of the nation's political division.

Tensions erupted most recently this month when members of the so-called "antifa" movement showed up at a march organized by a right-wing group called Patriot Prayer.

As police tried to keep order, fist fights broke out in a string of downtown parks fringed with aspen trees and dotted with plaques honoring Portland's founders and fallen World War II soldiers.

Videos from the conflict on social media show one man being knocked to the ground and kicked repeatedly as he covers his head with his hands. In another, a man lying on the ground is dragged away from a group of attackers, his face bloodied. In a third, two men — including one wearing homemade body armor — take swings at a third man who is backed against a wall with his arms raised.

Police made four arrests June 3 in and around the parks, which have become gathering places for dissent in this liberal city already known for near-weekly protests.

And in this city that patiently waits out traffic jams caused by protests, residents wondered how free speech had turned so violent.

Protesters here traditionally have demonstrated together for their causes. But over the past year a different type of political activism has shattered the unanimity normally seen among demonstrators, said longtime Portland resident Jon Baldivieso.

"It obscures better forms of political speech," he said. "It feels different when protests are more one-sided and not skirmishes between ideological factions. ...I've got very low patience for physical confrontation."

What is happening could be an expression of a deep sensitivity to a dark chapter of the city's history that's bubbling up as the rest of the country, too, becomes more politically polarized.

In the 1920s, the Ku Klux Klan had a strong presence in the city and by the 1980s, Portland was a hot spot for white supremacist groups, earning it the nickname "Skinhead City."

One of the most infamous attacks in Portland's racial history occurred in November 1988, when an Ethiopian immigrant was beaten to death by three white supremacists from the California-based White Aryan Resistance in front of his apartment.

The city was also the home base for Volksfront, a now-defunct white separatist organization founded in 1994, according to the Southern Poverty Law Center, which tracks hate groups.

While Patriot Prayer isn't considered a white supremacist or hate group by the Southern Poverty Law Center, its members march alongside right-wing groups promoting free speech rights by rejecting political correctness, said Ryan Lenz, an SPLC spokesman.

Those marches have drawn a forceful reaction from a left-wing movement known as the antifa that is dedicated to rooting out neo-Nazis and white supremacists, he said.

The 10-year-old group Rose City Antifa is one of the most organized of these loosely affiliated groups in the nation and also one of the oldest.

Individual antifa members remain anonymous, but the group's public Facebook page issued a call for members to show up June 3 to confront the "rising tide of fascism and the forces of structural and insurgent white supremacy" in Portland.

"If you think about it, Portland is home to this extreme leftist perspective ... but at the same time it is home to very hardcore racist groups going back to the skinhead groups," Lenz said.

Patriot Prayer has also held marches and rallies in many other cities around the U.S. West that have drawn violent reactions. But the Portland events have taken on outsized significance because of the stabbing deaths a year ago of two men who came to the defense of two young black women — one in a hijab— who were being harassed on a light-rail train by a Patriot Prayer sympathizer.

The man charged in the deaths, Jeremy Christian, was filmed making the Nazi salute at a Patriot Prayer rally a month before the killings.

Christian, who has pleaded not guilty, later told investigators he was not motivated by racism but was drunk and wanted to "do his free speech thing" when he shouted racist and anti-immigrant slurs on the light-trail train before the stabbings.

In the aftermath, Patriot Prayer leader Joey Gibson organized a pro-Trump free speech rally that attracted thousands from both sides to downtown Portland.

The ensuing chaos shut down much of the city's core and police arrested more than a dozen people amid widespread fighting.

Gibson, who is half Japanese and lives in Vancouver, Washington, across the Columbia River from Portland, said his followers are not racist but want the right to express themselves safely in a city that's very liberal. He hopes to put on another rally as soon as next month in an attempt to promote confrontation.

"We're way more diverse than any of these far-lefters, who are mostly white men," Gibson said in a phone interview with The Associated Press. The marches are intended to "stir the pot. It's to get people to oppose us, to violently oppose us."

Many Portland residents say they love their city's reputation for political dissent but are dismayed it has become a spotlight for violence.

At a park dedicated to a city founding father, accountant Mack Stilson used his lunch break to run through a set of bluegrass songs on his mandolin as a tour group strolled by snapping selfies and bike commuters whizzed past.

"This is sort of like an arena for their battles and I have a lot of trouble putting any weight behind it," he said of the protesters.

He added: "You can say whatever you want to say, whether you're extremely conservative or extremely liberal, and I think this town should be open to both. That's kind of what this town is all about."