In what has quickly become an iconic image of a modern America divided, a teenager wearing a "Make America Great Again" hat smilingly stares just inches from the face of Phillips as the Vietnam veteran beats a drum and sings the "American Indian Movement" song.
The images have been shared worldwide and sparked intense debate, fury and abuse as social media users, politicians, commentators and punters offer their interpretation of the scene.
Few comments have been as systematically and staunchly supportive of the teenagers as those made Sunday night by the conservative lawmaker from Kentucky.
Massie tweeted that following his initial discomfort at seeing the video, he chose to hang back, weigh up the facts before offering his thoughts: "because the narrative did not match what I know to be the character of these students."
Massie represents Kentuckys 4th Congressional District which stretches across Northern Kentucky and 280 miles of the Ohio River, including Covington.
The boys, quickly identified as Covington Catholic High School students had traveled from Kentucky to attend the March for Life, an annual anti-abortion demonstration at the capitol.
March for Life is something of a Covington tradition
Wearing "Make America Great Again" hats the boys are recorded from several angles surrounding a small group of protestors in front of the Lincoln memorial.
In several videos posted to social media, a smirking boy stands face-to-face with a protestors as the large group giggles, jeers, and clap.
The UK Daily Mail also reports that a Covington student has since claimed that Phillips has a history of racial vilification claims and forced his way into their "cheer circle" as a publicity stunt.
On Sunday, Massie describes the "honorable and tolerant" students as the victims.
"The honorable and tolerant students of Covington Catholic School came to DC to advocate for the unborn and to learn about our nations Capitol," he wrote. "What they got was a brutal lesson in the unjust court of public opinion and social media mobs."
"Ive now watched over an hour of other videos from 4 different cameras of the incident in front of the Lincoln Memorial. I urge everyone to watch the other videos before passing judgement."
"Would you have remained that composed at that age under those circumstances?" Massie rhetorically asks, without detailing the sources of the brutality.
"In the face of racist and homosexual slurs, the young boys refused to reciprocate or disrespect anyone. Even when taunted by homophobic bigots, which was obviously bewildering to them, they insulted no one."
Massie concludes by accusing the media of removing the context "of everything that was going on."
"Proud, not ashamed."
Despite the widespread and often visceral condemnation of the incident, Massie encourages the responsible parents and mentors of the boys - curiously absent during the incident - to be appreciative and gratified by their charges and their behavior.
"Parents and mentors of these boys should be proud, not ashamed, of their kids behavior. It is my honor to represent them."
By contrast, the school, in a statement condemned the actions of its students "towards Nathan Phillips specifically, and Native Americans in general."
"We extend our deepest apologies to Mr. Phillips. This behavior is opposed to the Churchs teachings on the dignity and respect of the human person. The matter is being investigated and we will take appropriate action, up to and including expulsion," the school added in a statement on its website.
INSIDER reports that a mother of one of the kids who wrote to Heavy.com said that the boys were provoked by a group of men who had been protesting before the Native American group arrived. "Did you hear the names of the people were calling these boys? It was shameful. Did you witness the black Muslims yelling profanities and video taping to get something to further your narrative of hatred??" the woman wrote, according to Heavy.com. The protesters have been identified as members of a group known as Black Hebrew Israelites, which is unrelated to Islam.
Last week in an interview with Fox Business Channel, Massie defended US Rep. Steve King following a national backlash regarding King's widely panned comments on white supremacy.
"In my presence, he's never said anything racist and so I'm not ready to censure a man based on a New York Times article," Massie said.
Massie: "the narrative did not match what I know to be the character of these students."
Massie is a staunch social conservative and deficit hawk who often calls for government spending cuts. He was first elected to Congress in 2012.
SEE ALSO: The mother of one of the boys who mocked a Native American activist blamed 'black Muslims' for the incident