Overnight, sporadic violence erupted in cities all across America. There is growing fury over the death of an unarmed black man in Minneapolis at the hands of police.
The anger has been simmering for days - but now it is rapidly escalating. It will prove difficult to contain because the protesters are demanding not a specific measure but a radical overhaul of America’s entire criminal justice system.
In Atlanta, a crowd attacked the headquarters of CNN. Quite why CNN was a target is difficult to fathom. But several activists I spoke to have claimed - falsely - that the network has used fake video of looting.
The furious mayor of the city, Keisha Lance Bottoms, told the protesters: “This is not a protest. This is not in the spirit of a Martin Luther King. You are disgracing this city.”
There were also clashes between black activists and police in dozens of other cities, including New York and Los Angeles. In Brooklyn, video showed what appeared to be a police officer using a car door as a weapon against a protester.
All of these angry protests were ignited by the death of George Floyd in Minneapolis this week. The African-American was a suspect in a minor, non-violent crime.
He was arrested by a group of four police officers. One of them, Derek Chauvin, kept his knee on Floyd’s neck for 7 minutes, despite obvious signs that the man was struggling to breathe.
Officer Chauvin has now been charged with third-degree murder. But that will not be enough to dissipate the protests.
At a protest in Washington DC outside the White House several young activists told me that they now want all four officers to be charged with murder, followed by a compete overhaul of American police forces.
In multiple locations, the clashes have only exposed the police to fresh allegations of brutality and insensitivity.
In Louisville, Kentucky, it appeared that police were deliberately firing rubber pellets directly at a reporter and her cameraman.
The anger of the protesters is directed at the police, at prosecutors and at the President. Above all, it is aimed at racial injustices - and many of those have been amplified during the pandemic. African-American businesses and employees have been uniquely vulnerable to discrimination.
So America faces a long, hot, tumultuous summer. The country is enduring a pandemic, grave economic dislocation resulting from the lockdown, mass unemployment, a bitter presidential election campaign and - now - severe racial turmoil.
Any one of those events would present a serious challenge to America’s prosperity and stability.
Together, they amount to more than a crisis. They represent a national emergency.