President Trump, in part, was right. There is blame to go around for the unrest in Charlottesville. There is fear, intolerance, demonization and growing hatred on both the extreme left and the extreme right. But despite what Trump has claimed, repeatedly, in his public statements since the tragic events there, the willingness to employ organized violence to achieve political goals remains a signature quality of only one side. And it’s not the left.

Extremism on the left is real. It can be seen in attempts to stifle the free speech of conservative speakers on university campuses (as at Middlebury and Berkeley); in the belligerent attitudes toward corporations and capitalism expressed, for instance, by some fringes of the Occupy Wall Street crowd and anti-globalization protesters; and among anti-Zionist movements that peddle conspiracy theories (such as the contention that Jews control U.S. foreign policy) to delegitimize Israel. Yet all of this falls well short of the methodical, organized and strategic violence and incitement embraced by right-wing extremists, whose leaders profess faith in the necessity of the fight. Nothing the left can do today even comes close to that — and hasn’t for decades.

Although the American left was never as fully at ease with revolutionary violence as were its European counterparts (who were reared on Robespierre and Marx), it often took up arms. Labor unions battled constantly with railroad barons, industrial tycoons and mining bosses during the Gilded Age. Even while outnumbered and outgunned, usually by private armies that enjoyed the backing of law enforcement and state militias, workers fought in bloody clashes that left dozens dead on battlefields such as Chicago’s Haymarket Square (1886) and West Virginia’s Blair Mountain (1921).

[Who are the antifa?]

The New Deal helped calm labor-management tensions, but for many younger activists who came of age in the postwar era, violence remained a key strategy — even a way of life. Inspired by the Black Panthers’ embrace of violence for self-defense, and enraged by the escalating war in Vietnam, antiwar protesters from New Left organizations such as Students for a Democratic Society (SDS) sought to “bring the war home” to end the fighting abroad. This concept culminated in the rioting during the 1968 Democratic convention and on university campuses. Radical offshoots including the Weather Underground and the Symbionese Liberation Army took things even further: The former bombed government buildings, and the latter committed homicide, robbery and, famously, kidnapping.

But since the 1960s, left-wing movements in the United States (and in the West writ large) have gradually turned away from violence. There are three main reasons for this.

The first is practical: It backfired terribly. The Vietnam War protesters initially believed that their country was beyond redemption, so a revolution was imperative. This alienated the general public, helped unify a deeply divided conservative movement and emboldened Richard Nixon’s “silent majority.” Violence proved counterproductive to ending the war; if anything, it helped prolong it. The leaders of the New Left, who consciously distinguished themselves from the “liberal center” through their obstinate allegiance to a romantic revolutionary spirit, eventually admitted this. Tom Hayden, a founder of SDS and a lifelong social justice crusader, later expressed regret over his uncompromising positions. And Mark Rudd, a leader of the Weather Underground, sounded an unequivocal mea culpa. “Much of what the Weathermen did had the opposite effect of what we intended,” he conceded. “. . . We isolated ourselves from our friends and allies as we helped split the larger antiwar movement around the issue of violence. In general, we played into the hands of the FBI. . . . We might as well have been on their payroll.”

[The whole point of Confederate monuments is to celebrate white supremacy.]

The left’s second reason for rejecting violence was even simpler: There were better ways to get things done. The civil rights and feminist movements showed that nonviolent protest could achieve tangible political goals. When the Rev. Martin Luther King Jr. made the case for civil disobedience in his Letter From Birmingham City Jail, it was not based only on ethical principles of Christian brotherly love but also on shrewd political calculations. “The purpose of our direct action program is to create a situation so crisis packed that it will inevitably open the door to negotiation,” King wrote. By provoking a crisis of conscience for ordinary Americans, civil rights leaders made the political system work for their cause, leading to the Civil Rights Act, the Voting Rights Act and other anti-discrimination laws. The lesson: There was no point in challenging the legitimacy of a government that enabled them to accomplish many, albeit not all, of their goals through the democratic process.

The third and most important reason for giving up violence can be found in the new makeup of the American left. Emerging out of the rubble of the 1960s, the modern left, which coalesced around George McGovern’s quixotic 1972 presidential run, effectively represented a gathering of fugitives. African Americans, Hispanics, women, gay men and lesbians, Native Americans, and workers: These long-ostracized groups, which came to replace the New Deal coalition anchored by the white working class, were the very peoples against whom violence had been done for so long. Their painful histories made them instinctively averse to, and intolerant of, political violence. Those who had survived lynchings, beatings, bombings, sexual violence, forced removals and economic exploitation were least disposed to employ them in return. In 1972, those groups were often on the far left, but they eventually became the spine of Barack Obama’s electoral coalition.

Although the American left’s transition away from violence was as much a strategic choice as a moral one, the seeds of violence are still embedded in its historical consciousness. That is why lone-wolf attackers like James T. Hodgkinson , who shot and critically wounded GOP Rep. Steve Scalise during a baseball practice in June, and occasionally violent groups such as antifa, which have clashed with right-wing protesters, are worrisome. But they are not the same as their counterparts on the right. Antifa is mostly anarchist in nature; its members are suspicious and dismissive of the left’s embrace of government institutions. More important, it is loosely banded, disorganized and low scale. Brawling on campuses, throwing rocks or vandalizing property is reprehensible and illegal. But it is incomparable to the scope and breadth of organized violence demonstrated by the extreme right.

[Robert E. Lee is my relative. Take the monuments down.]

While the far left has distanced itself in recent decades from political violence, the far right has headed in the opposite direction: The more activists have failed to preserve their waning political influence and achieve their goals through the democratic process, the more inclined they have become to take up arms and challenge it. The left has successfully integrated into most political, economic and cultural facets of the country, but members of the extreme right say they have been devastated by the economic effects of globalization, disempowered by multiculturalism and disenfranchised by the election of the nation’s first African American president. This sentiment has led to the rise of militia culture and violent resistance on unprecedented scales since the 1990s; it sparked the deadly standoff in Ruby Ridge, Idaho, 25 years ago, climaxed in the Oklahoma City bombing and has persisted, more recently, with the massacre of African American worshipers at a Charleston, S.C., church.

Organized militias that are well armed, well trained and well networked have seen a particular spike since the beginning of the Obama presidency. The Southern Poverty Law Center reported last year that 276 militias operate in the United States, a 37 percent increase from the previous year. Although they are not monolithic — the groups include white supremacists, Christian millenarians, Second Amendment champions and self-appointed border guards — they all revile the federal government. “Sovereign citizens” are armed to the teeth and willing to challenge officials, as they did in last year’s armed standoff at the Malheur National Wildlife Refuge in Oregon. Many such militiamen have killed or injured local police. They pose a greater threat than the Islamic State or al-Qaeda, according to a 2016 U.S. government report: “Of the 85 violent extremist incidents that resulted in death since September 12, 2001, far right wing violent extremist groups were responsible for 62 (73 percent) while radical Islamist violent extremists were responsible for 23 (27 percent).”

This doesn’t mean the left is inherently superior. But it has cleansed itself through a painful process of introspection. And if American democracy has any chance of convalescing from the fever of intolerance that has seized it since Trump’s election, people on the right must take a similarly long, hard look in the mirror. If not for their party’s sake, then at least for the country’s.

outlook@washpost.com

Yoav Fromer teaches American history and politics at Tel Aviv University and Yeshiva University. He is at work on a book about Daniel Patrick Moynihan and American liberalism.