(CNN) An enraged White man thrusts the sharp point of an American flagpole toward a helpless Black man. A snarling police dog lunges at a civil rights protester. A White police officer presses his knee on the neck of an unconscious Black suspect.
Each of these blistering images from history changed the way Americans talked about race and exposed truths that many had long denied.
The January 6 assault on the US Capitol has added some new entries to that grim gallery. Many Americans are still reeling from seeing images of what's been called a "White riot" -- an assault on Congress by supporters of President Donald Trump, which left five people dead.
It's been described as "the most dramatic challenge to the US democratic system since the civil war," but its impact on racial justice has been undersold.
Many have noted the racial dimensions to the insurrection, in which at least one Capitol rioter carried a Confederate flag. One commentator said that if the mob was Black, the Capitol's marbled "hallways would be red with their blood." House Speaker Nancy Pelosi said the mob chose their "whiteness over democracy."
But I believe the Capitol riot could have a far-reaching impact on racial justice in America -- bigger, even, than last summer's George Floyd protests. In some ways, it already has.
Here are five reasons why the Capitol insurrection offers an opportunity for transformative change.
Consider the impact of last year's George Floyd protests -- what they did, and what they failed to do.
Floyd's death last May at the hands of a White police officer in Minnesota sparked what some consider the largest protest movement in American history.
An estimated 15 to 26 million Americans of all races took to the streets to protest police brutality last summer. Local and state politicians proposed laws to reform policing and combat racism. Corporations posted Black Lives Matter on their websites. Sales of anti-racism books soared.
But here's what the protests didn't do: They didn't stop Trump from getting 74 million votes six months later in November's election -- more than any president before him.
Trump may be leaving office, but his corrosive influence isn't going away. Critics say the President is responsible for returning White supremacy to mainstream politics. For years, a large segment of White America continued to support him no matter what he said or did. The Floyd protests didn't loosen Trump's hold on the Republican party or large swaths of White America.
The fallout from the Capitol assault, though, may cause irreversible damage to Trump's brand. The House of Representatives impeached him -- again -- for inciting violence against the US government. Some Republican lawmakers are now openly breaking with him. His approval rating has sunk to its lowest level ever. Corporations and banks are cutting ties with the Trump Organization.
"His entire legacy was wiped out yesterday," Rep. Nancy Mace, a Republican freshman from South Carolina, told CNN a day after the Capitol assault.
It's true that Trump remains the most dominant force in the Republican Party. It may be premature to write his political obituary. But the stain of the Capitol riot may follow him, his family and their supporters in Congress for the rest of their lives.
The shame of the Capitol riot will haunt many of Trump's followers as well. "The heartbeat of racism is denial," the race scholar Ibram X. Kendi once said. "The American creed of denial — 'I'm not a racist' — knows no political parties, no ideologies, no colors, no regions."
It was easier for a segment of White America to deny their racism during the Floyd protests. They could say the four police officers charged in Floyd's death were just a few bad apples. They could tune out debates about abstract terms like "systemic racism." They could attack a clumsy political slogan like "defund the police" to justify defending the status quo.
The Capitol riot, though, has made it much more difficult for White Americans to deny our country has a huge problem with White supremacy. It's forced many Americans to see how dangerous White supremacy is in a way that the Floyd protests did not.
You can see this shift in the language people are using to describe members of the Capitol mob. They've called the assault an "insurrection" and a "coup from below" and argued that White supremacy is incompatible with democracy.
Few, if any, described the accusations of police brutality that fanned the Floyd protests in such a stark way.
The images of the Capitol mob also show how White supremacy is wielded by many ordinary White Americans. Not everyone in the mob was a White supremacist. But the White people who waved a Confederate flag in the Capitol Rotunda, built a makeshift gallows on the Capitol grounds and forced lawmakers to flee for their lives represented a broad swath of America.
"These were not just the Trump loyalists of lore, that economically marginalized, over-elegized white working class of the heartland, columnist Farhad Manjoo wrote in The New York Times.
"No, the crowd that stormed the Capitol was a big tent of whiteness, a cross-section of American society bridging divisions of class, geography and demography. They were doctors and lawyers, florists and real estate agents, business executives, police officers, military veterans, at least one elected official and an Olympic gold medalist. They'd all come to coup for America."
The Capitol rioters didn't just embarrass themselves -- they embarrassed the country they profess to love.
The riot occurred as the US is jockeying with Russia and China for global influence. Russia and Iran ridiculed the US on social media over the riot, while Turkish President Recep Tayyip Erdogan, whose government has been accused of human rights violations, called the mob "a disgrace for democracy." The riot occurred the same week that China cracked down on Hong Kong's democracy movement with mass arrests.
"There is no way to ... ignore the power of the message that these events send to both the friends and the enemies of democracy, everywhere," the historian, Anne Applebaum, wrote in a recent essay. "The images from Washington that are going out around the world are far more damaging to America's reputation as a stable democracy than the images of young people protesting the Vietnam War several decades ago, and they are far more disturbing to outsiders than the riots and protests of last summer."
But the Capitol crisis also presents an opportunity for racially transformative change at the federal level. It's happened before, under similar circumstances.
The US was locked in a global struggle with Russia for the hearts and minds of people when the civil rights movement took flight in the 1950s and 1960s. Civil rights leaders leveraged our Cold War rivalry to help pass sweeping civil rights laws.
The 1963 civil rights campaign in Birmingham, Alabama, offered a classic example. Images of Black protesters being attacked by police dogs and sprayed with firehoses were beamed around the world. Foreign governments attacked American leaders for their hypocrisy in preaching the virtues of democracy abroad while hanging "Whites only" signs at home.
White supremacy became a national security issue. The ugly fallout from the protests in Birmingham forced President John Kennedy to propose a bill that became the 1964 Civil Rights Act, which outlawed segregation in public accommodations and made employment discrimination illegal.
In a nationally televised speech announcing his bill, Kennedy said the US was "committed to a worldwide struggle" to promote freedom, and now was the time for the nation to "fulfill its promise."
"We preach freedom around the world, and we mean it, and we cherish our freedom here at home," Kennedy said, "but are we to say to the world -- and much more importantly, to each other -- that this is the land of the free except for the Negroes?"
The Capitol mob has created the same type of political environment for change. The Floyd protests sparked some changes at local and state levels and led a cultural shift among Whites who began to consider their own racism. But they have yet to bring any racially transformative changes at the federal level.
The Capitol insurrection, however, has created the conditions for such potential changes under President-elect Joe Biden.
Consider the political appetite for racially transformative change in a new Congress where both Houses are controlled by the Democrats and the GOP is now in disarray.
Start with voting rights reform. There is no racial issue more important than voting rights. A famous 19th-century Supreme Court decision declared that voting is "a fundamental political right, because [it is] preservative of all rights."
It's easy to forget, but the Capitol riot was sparked by some voters' distrust of elections. Trump and some Republican lawmakers claim, without evidence, that the Presidential Election was stolen by voter fraud. Progressives counter that Republicans employ such tactics as voter purges, restricting early voting and closing polling stations in predominantly Black communities.
There's a growing sense that America's electoral system is broken.
One voting rights expert says this is the perfect opportunity for Congress to repair the damage done by the Supreme Court's 2013 Shelby County v. Holder decision, which opened the door to voter suppression tactics by removing a key enforcement mechanism of the Voting Rights Act.
Democrats could pass an updated version of what's now being called the John Lewis Voting Rights Advancement Act, which would block voter purges, ensure easy access to early voting and restore federal supervision of voting changes in states with a history of voter suppression, says Richard L. Hasen, a professor at the University of California, Irvine.
The new Congress could also cite the mayhem at the Capitol building as a reason to crack down on social media platforms where users spread misinformation about voter fraud. Several Democratic leaders say social media helped spark the riot.
"Congress was attacked ... by a mob that was radicalized in an echo chamber that Facebook and other big platforms created," said Democratic Rep. Tom Malinowski of New Jersey.
These potential changes -- new federal laws expanding voting rights and regulating social media platforms -- aren't as dramatic as the throngs of protesters that flooded American streets last summer. But they are potentially more racially transformative.
Many Americans are still stunned by what happened at the Capitol. An outgoing President who many consider to be a White supremacist tried to incite lawmakers and citizens to overturn a legitimate election and block an incoming administration which includes the nation's first Black and South Asian vice-president.
For some, the Capitol mob's actions reminded them of White terrorism in the Jim Crow South. White militia groups such as the "Red Shirts" used violence to intimidate voters and attack Blacks. In 1898, an armed White mob staged a coup against a multiracial government in Wilmington, North Carolina, and killed more than 60 Black people.
There's also a growing recognition that what the Capitol mob did is nothing new.
"Since the nation's founding, a large portion of White citizens have embraced free and democratic elections only when the political system did not require them to share power with people of color," the historian Joshua Zeitz wrote in a recent essay for Politico.
Arnold Schwarzenegger, the Austrian-born former Republican governor of California, said it reminded him of Kristallnacht — the "Night of Broken Glass" — an infamous episode in 1938 in which a mob of Nazi sympathizers rampaged through Jewish neighborhoods in Germany, killing Jews and destroying synagogues and Jewish-owned stores.
"Wednesday was the day of broken glass right here in the United States," Schwarzenegger said. "The broken glass was in the windows of the United States Capitol. But the mob did not just shatter the windows of the Capitol. They shattered the ideals we took for granted. They did not just break down the doors of the building that housed American democracy. They trampled the very principles on which our country was founded."
How the Biden administration channels the outrage of people like Schwarzenegger will be critical in the weeks ahead. Many Americans see the Capitol rioters as patriots and freedom fighters. Some on the far right have praised the assault as a "second revolution."
How future Americans view the Capitol assault will also depend on what vision of America prevails -- Trumpism or the egalitarian principles that Schwarzenegger evoked.
If the forces that drove rioters to ransack Congress gain permanent political power, the notion of citizens choosing their Whiteness over democracy won't seem so offensive.
But if America fulfills what Kennedy called "its promise," those images of White supremacists in the Capitol Rotunda will join the shameful gallery of photos that includes the 1963 Birmingham protests.
The rioters will be viewed as symbols of a bygone America its citizens have left behind.