Details are slowly emerging about the fatal vehicular attack in Charlottesville, Virginia, on Saturday. James Fields, a 20-year-old man, has been charged for the assault, which killed one person, 32-year-old Heather Heyer, and injured 19 others. The attack sparked an immediate political controversy after President Donald Trump declined to specifically condemn white nationalism, instead blaming the violence “on many sides.”

The ramifications of the attack are wide ranging—for the increasingly visible white supremacist movement, for the mainstream conservatives that give them safe harbor, for the liberal Virginia college town beset by these torch rallies, and for the victims of racism and bigotry.

The attack also threatens public space, an amenity that is both scarce and necessary for democracy. The idea of the public square is under attack. And the extremist alt-right is waging a campaign to shut down the public square, using both violence and intimidation, especially under open-carry laws.

Public space as public sphere is a concept that dates back to late 19th century Britain. In 1866, United Kingdom Home Secretary Spencer Walpole banned the Reform League from hosting a universal manhood suffrage rally in London’s Hyde Park. The Reform League fought back, arguing that the park belonged to either the public or the crown. The Home Secretary was neither. When he did not stand down, rioting followed, and on the third day of violence, some 200,000 people knocked down the gates and stormed Hyde Park. Today, a mosaic marks the Hyde Park Railings Affair at the site of the so-called Reformers' Tree, which was burned during the riots; the charred tree served as a notice board and rallying point, a symbol of the right to assembly.

“Those rights we take as ‘immemorial,’ such as the right to assemble in and use public space, are not only relatively new, they are always hotly contested and only grudgingly given by those in power,” writes Don Mitchell in The Right to the City: Social Justice and the Fight for Public Space. “Always hotly contested: rights over and to public space are never guaranteed once and for all.”

Driving a car into a crowded pedestrian mall is a tactic that the far right adopted from ISIS—and Saturday’s attack was the first such vehicular terror attack in the United States. It seemed as if it were calculated to inflict maximum damage. Charlottesville’s Downtown Mall is one of the most successful pedestrian malls in the country, a core feature of public life in the city. It is one of the few car-free pedestrian malls in America that has lasted for decades.

A brief history: Charlottesville’s Downtown Mall was designed by Lawrence Halprin, the landscape architect who made the Franklin Delano Roosevelt Memorial in Washington, D.C., and Ghirardelli Square in San Francisco, among many other beloved public plazas. The city launched the Downtown Mall project in 1973 as a revitalization effort. With businesses fleeing urban corridors for suburban shopping strips, the city stepped up with a major overture to turn around its downtown’s fortunes. It worked.

Charlottesville’s Downtown Mall has been the site of regular protests since last year, when the city declared its intent to remove a Confederate statue celebrating Robert E. Lee. White supremacists old and new, from the Ku Klux Klan to the Proud Boys, have descended on the mall in rallies to support the statue—rallies that have garnered increasingly large anti-fascist counter-protests.

Saturday’s “Unite the Right” rally was in some sense about public space. Its organizers aim to defend a statue that affirms their history, one that affirms white supremacy as official power. They also engaged in a legal battle to stage the protest in their park of choice, Emancipation Park—one that the city deemed unsafe for a white supremacist rally. And in the hours before the rally, they won that fight, potentially upsetting the city’s safety preparations.

That is the textual explanation: This is a rally about a statue in a park. That’s how the rally’s organizers frame their demonstrations, as conservative and preservationist in nature. But the alt-right’s fight is also with public space. Fascism rejects the free flow of speech and ideas. It is an attack on the public sphere. Saturday proved that.

Intimidation is also an attack on public space. And in open-carry states, Virginia among them, the far right uses weapons to chill free speech. Consider this scene from Charlottesville:  

In open-carry states, lawmakers have visibly ceded law enforcement authority to racist provocateurs. Open-carry rights do not extend to black people, not in any safe or meaningful way, so the terms of this “debate”—between minorities trying to live and whites trying to suppress them—cannot be evened. Open carry is incompatible with the notion of public space and free speech. A public square is not possible in states with open-carry laws.

Public squares are vulnerable to car assaults because they are designed (ideally) to be broad, open, and accessible to many people for many purposes. A car assault in May in New York’s Times Square—perhaps America’s most famous public square—triggered fears that it had been a terrorist attack. (Instead, the driver was under the influence of serious drugs and afflicted by mental problems.) One person died in the Times Square crash, and 22 were injured. The crash might have proven even more fatal, were it not for the anti-ram steel security bollards that stopped the car, one feature among many added since 2010 to make Times Square safer for pedestrians.

Those bollards wouldn’t work on 4th Street in Charlottesville, which is open to traffic and crosses the pedestrian mall. The problem in Charlottesville was not a design problem, but a philosophical one. Fascism is not concomitant with a public square. It is not a competitive idea that can be weighed equally with others in deciding how to guarantee the First Amendment right to free assembly. White supremacists are attacking a feature of democracy itself.