Catholic school students in Trump hats. A Native American elder beating a drum. Black Hebrew Israelites hurling bigotry.

This chance encounter on the National Mall that winter afternoon blew up into a near perfect storm fed by the kinds of divisive social issues roiling the nation.

Liberals and conservatives alike saw what they wanted to see in videos captured on smartphones at the scene. It seemed as if everyone with a Twitter account had an instant opinion as the first video clip, reflecting only a brief portion of the Jan. 18 encounter, raced across the world.

In the aftermath, USA TODAY analyzed more than 3 million tweets and thousands of public posts on Facebook, from the moments after the video of Covington Catholic students' encounter with Native American activist Nathan Phillips was posted to President Donald Trump's tweets days later.

The volume and velocity provide an illuminating example of how social media and the news media can be exploited to fuel outrage in a deeply divided country, even as the full picture of an event is still forming.

All it took was a nudge from a few suspicious accounts on Facebook and Twitter. Partisan fervor mixed with high emotions did the rest.

Nearly 24 hours after the first published story, more than 30,000 tweets an hour mentioned Covington.

More:What to know about Black Hebrew Israelites

Tweet after tweet fed the outrage machine, swiftly condemning the students, who appeared to critics to have surrounded and mocked Phillips at an Indigenous Peoples March in Washington, D.C. Then media coverage began to accelerate. Among the students who were attending a March for Life anti-abortion rally in the capital, Nick Sandmann was singled out for the way he smiled at Phillips as the two stood face to face. Religion scholar Reza Aslan wrote on Twitter: "Have you ever seen a more punchable face than this kid’s?”

Finger-wagging from millions of strangers quickly escalated to threats. "Name these kids," comedian Kathy Griffin demanded of her 2 million followers. "I want NAMES." A film producer tweeted – then deleted – a scene from the movie Fargo: "#MAGAkids go screaming, hats first, into the woodchipper."

Even after a longer video emerged showing that the confrontation began after a group known as the Black Hebrew Israelites targeted the boys and began yelling insults at them, which Sandmann called "hateful things," no one could agree on what happened. A month later, they still haven't.

An investigation conducted on behalf of the Diocese of Covington concluded last week that the students did not instigate the incident and made no "offensive or racist statements," though the report acknowledged some students made a "tomahawk chop" gesture. The investigation determined, as did reporting by some news outlets, that Phillips had approached the students as they exchanged words with the Black Hebrew Israelites, contradicting what he first said when describing the standoff. Phillips said he stepped between the students and the Black Hebrew Israelites to defuse the "volatile" situation. But fuller video of the entire encounter shows Phillips walk past the Black Hebrew Israelites and up to the students.

Phillips, a member of the Omaha tribe, responded to the school's report by saying the students were disrespectful: "I ask everybody to remember what we all saw – students performing a culturally appropriated ‘school chant’ and the tomahawk chop just feet away from me on that fateful day."

Lance Soto, an indigenous leader from Covington, told the Cincinnati Enquirer: "I hope that our people realize that it’s not up to white people to determine what is racist or derogatory toward Native Americans."

Bishop Rev. Roger Foys of the Diocese of Covington argued the reaction from the students on the National Mall was expected and "one might say even laudatory."

"The immediate world-wide reaction to the initial video led almost everyone to believe that our students had initiated the incident and the perception of those few minutes of video became reality," Foys said in a letter sent to parents last week. "In truth ... our students were placed in a situation that was at once bizarre and even threatening."

The ease with which political divisions can be exploited on social media and are then amplified by the news media is a lesson for our time, says Klon Kitchen, senior research fellow for technology, national security and science policy at the Heritage Foundation. But, Kitchen says, the real problem is us.

"We are building thick bubbles of information around ourselves, where it's always self-reinforcing, where we are losing any kind of perspective on alternative views and where we are very excited about participating in the public takedown of people's reputations," he says. "It's not the only time we've seen this and it won't be the last."

The evolution of a controversy

The controversy began when observers, such as college student Kaya Taitano, pulled out their phones to film the encounter on the National Mall. But its viral spread points to the little-noticed role that social media accounts of unknown origins can play in weaving inflammatory content into timelines and news feeds.

Taitano attended the Indigenous Peoples March and told the Guam Daily Post that Phillips was chanting and described his actions as cleansing the negative energy in the area. The one-minute video clip she posted on Instagram, showing a close-up of Sandmann and Phillips, quickly drew attention. "The amount of disrespect.... TO THIS DAY," Taitano wrote hours after the incident.

"Those kids were so lucky that elder stepped in," Taitano said.

Video of the confrontation was spotted by @2020fight, a Twitter account with 41,000 followers using the name "Talia," which added a message that, within hours, triggered an explosive political moment: “This MAGA loser gleefully bothering a Native American protestor at the Indigenous Peoples March.” Twitter later determined that @2020fight was a suspicious account, but the message spread.

Boom. First liberal activists expressed outrage, then celebrities, commentators and journalists. The clip quickly had more than 10 million views and 28,000 retweets. By early morning Jan. 19, people were being drawn into the online squabble by the thousands.

Twitter eventually suspended @2020fight for "deliberate attempts to manipulate the public conversation on Twitter by using misleading account information" after CNN Business raised suspicions about it. The account was then reactivated and NBC News reported that a teacher likely ran the account, which the person later deleted. Twitter did not explain why it reactivated the account.

But the video was being spread by other Twitter accounts and was gaining traction on Facebook, too, where pages seemingly run by activists raced to share it.

About 2 a.m. on Jan. 19, well before the story went viral, a Facebook page called REAL Mexican Problems posted it, attracting more than 1.5 million views and nearly 22,000 shares. "This is Amerikkkan arrogance at its worst," the post read.

The page, created in 2013, often shares indigenous themes and memes and describes its mission as "abolishing white supremacy!" But the only contact information for the page is a phone number for the White Knights of the Ku Klux Klan. An inquiry from USA TODAY prompted Facebook to investigate the page.

Whoever lit the spark, the firestorm raged on its own.

Dominating news feeds

Angela Beers, a psychologist from the indigenous community in Detroit who was unable to attend the march in Washington, spotted the video and wrote a Facebook post to defend her friend against a growing barrage of criticism.

"Despite what a lot of people seemed to be confused about, Nathan offered prayers to this individual in a situation that could have been much worse. Nathan's act of compassion was made to look like an act of instigation," she said. "The situation was defused. Everyone went home. There were no arrests. There was no bloodshed. He did the right thing."

Amanda Blackhorse, an activist from Phoenix, attended the Indigenous Peoples March but left before the incident. The next morning, a friend flagged the video. "I was just like so shocked," she said. "I immediately shared it."

Her post received nearly 500,000 video views and was shared about 6,000 times, including by a Facebook group with more than 70,000 members: I Acknowledge A War On Women Exists. "When I posted, I didn't realize it was going to turn into the thing it turned into," said Danielle Barnhart, a New York woman who shared the post to the group.

James Reader, who created the page about three years ago and used to run a page called Reverb Press that Facebook shut down last year, says conservatives and liberals on Facebook routinely work to quash stories that don't fit their views and boost those that do.

"The game is to try to dominate people's news feeds," he said. "We most definitely want to influence the way mainstream media covers stories and events."

And that's seemingly what happened by the time local and national media picked up the story.

The River City News, which covers the city of Covington, posted a story on Facebook at 10:50 a.m. the day after the march with the headline "Video Appears to Show Covington Catholic Students Swarming Native American Marcher." The Cincinnati Enquirer, a USA TODAY Network newspaper, also picked up the story about an hour later, citing the video and published a story with the headline "Covington Catholic faces backlash over video.” By the time national news outlets, including USA TODAY, began reporting on the story, the video had potentially reached millions.

The parents of one teen who was mistakenly identified by the angry mob on Twitter were harassed at a family wedding. A Colorado teacher was placed on leave after misidentifying another teen, accusing him of training with "Hitler youth."

More video footage surfaced two days after the incident and, just as quickly as the story spread, so too did questions about what really happened. Media, including USA TODAY, followed up the initial coverage with stories and social media posts that focused on the revelations in the longer video, and pursued other developments.

The political winds shifted sharply. Now conservatives were raging against those who had rushed to denounce the Covington Catholic teens.

An enemies list #VerifiedBullies was crafted to out liberals who had behaved badly. Conservatives rallied around the hashtag #StandWithCovington. Trump weighed in twice on Twitter, saying the kids were "smeared" by the media.

Chastened, some who criticized the students apologized or deleted their social media posts. That included Hollywood producer Jack Morrissey, who deleted his tweet about the woodchipper comment and told The Wrap: “It was just a fast, profoundly stupid tweet."

This week USA TODAY reviewed and deleted a Twitter post that cited language from a story: "The crowd of students, some of whom wore MAGA caps, mocked Native Americans while chanting 'Build the Wall' and using derogatory language." The post was removed today because the underlying events have been disputed as additional video has surfaced and the description should have been attributed to Phillips as his view.

Three days after the encounter, the conservative backlash had reached a fever pitch. Fox News' Todd Starnes lashed out at news reporters, calling them "thugs with press passes" who had intentionally endangered young people with reckless coverage "simply because they were wearing #MAGA hats." Julie Irwin Zimmerman, a Cincinnati writer, wrote a mea culpa in The Atlantic: "I Failed the Covington Catholic Test."

Threats made against the students by public figures – and Twitter's failure to remove them – continued to inflame the political right. Hundreds of social media posts were reported to law enforcement in addition to direct threats against students, parents and the school.

'Cultural crisis'

Weeks later, the national fury has died down, but the embers still glow.

Many on the political left still defend their initial take after seeing the footage of Phillips on the steps of the Lincoln Memorial. USA TODAY reached out to Griffin and Aslan to see if they stood by their tweets. Neither responded.

Soto, a member of the Cocopah tribe and leader within the Indiana and Kentucky chapter of the American Indian Movement, told the Cincinnati Enquirer last week that the local American Indian Movement chapter has called for a public apology to Phillips and new curriculum on Native American history. The chapter also wants all Covington Catholic staff who accompanied the teens to Washington, D.C., to be fired.

"I saw young men mocking and disrespecting an elder," Soto said, "and it made me sad to think about how much work we have to do locally in order for our Native Americans to be recognized as actual human beings."

Lawyers representing Sandmann and his family told the Cincinnati Enquirer they are preparing for possible libel and defamation lawsuits. Just this week, Sandmann’s lawyers announced they were suing The Washington Post for $250 million, saying the newspaper's coverage “attacked, vilified, and threatened Nicholas Sandmann."

Propelled by the speed of the Twitter bullhorn and the news cycle, this polarization is only getting more extreme, says Whitney Phillips, assistant professor of communication and rhetorical studies at Syracuse University.

That a few taps on a screen can cause so much strife and chaos speaks more to the current cultural crisis in the United States than the state of media or social media, she says.

"It's not so much that America is being manipulated. It's America being harnessed," Whitney Phillips said. "You identify a pile of kindling and then you direct your accelerant there. But the kindling has to be there first in order for these campaigns to work."

More: Columnist Kirsten Powers: I'm not proud of the role I've played in toxic debate.