I think you meant violent, but the Left also spreads like a virus, so they are also virulent. All still true.

I think I'd like to add in some additional info about the history of Leftwing political violence.

I think this video of The angriest I've ever seen Michael Knowles get, shows what it looks like when a relative normie discovers the beginnings of just how bad it really is.

There have been 3 major periods of Leftist violence in America, and none of them are referred to as Leftwing terror campaigns.

• The Labor / Coal Wars of the late 1800's
• The Red Scares of the Interwar Period
• The Days Of Rage Campaign of the 1970's

All of these comprised hundreds if not thousands of shootouts, bombings, riots, assassinations, and more, normally as part of a wider terror campaign internationally. The most recent one, honestly, was the 2020 Black National Socialist Kristallnacht, which also expanded into Canada's Red Terror against Catholics and the burning of 16 churches, and the vandalization of 40 others.

Of all the major terrorist attacks or offensives in history, here's the ones nobody talks about, and were all Leftwing:

• Wall Street Bombing - 30 killed and over 100 wounded in the largest terrorist attack of it's time
• Sterling Hall Bombing - 1 killed, but the Communist conspirators almost entirely got off. The primary conspirator served only 7 years, became a hot dog vendor, and said he'd do it again. It was the inspiration for the OKC bombing. Canada refused to extradite them on terrorist charges because they could have faced the death penalty.
• Burning of Kent State ROTC building - Attempt to murder 300 cadets while they slept, and is why the National Guard were at Kent State in the first place. When the Ohio National Guard were separated and attacked by rioters, they shot into the air and hit several random students. That is the only part that anyone hears about.
• 1954 Congressional Shooting - Puerto Rican Separatists attempted to machine gun the entire US Congress wounding 5 people before being shot at and captured by the Sergeant At Arms. (The second attempt to murder most of the legislature was the Baseball game shooting).
• MOVE Firefight (1978) - Black Separatist Communist organization takes over a portion of Philadelphia in an insurrection and kills 1 police officers and wounds 13 others in a major gunbattle
• MOVE Siege (1985) - The same group does the same thing, but this time after another major gunbattle, they are hit with an incendiary bomb to force them out of the building. You always hear about the bombing, but never why.
• Attica Prison Hostage Crisis (1971) - 43 Killed, 42 hostages were taken, 90 Wounded. Bloodiest prison "riot" that I can even think of in US history

And just to be clear only The Wallstreet Bombing is even referred to as a Leftist Terrorist attack on Wikipedia.

There's so much more. It's unfathomable. Political violence from Leftist ideology represents the vast and sweeping majority of all political violence in American history. There are fucking enormous amounts of Leftist violence in America and history and absolutely none of them are affiliated with the Left. Here's a good one:

Jonestown was a Leftist suicide event. People don't even talk about the fact that Jim Jones was directly involved in California Democrat politics, including Diane Feinstein directly. Jonestown was a Leftist Commune. He decided to kill all of his followers when it appeared that the local government would have him arrested, and his appeals to the Soviet Union were rejected. When Jim Jones's men killed two US congressmen who came down to work with him on letting people go, that's when he decided to execute everyone.

I bet you no one in any documentary of any stripe ever said a word about how well Jim Jones was connected to the California Democrats, and how his cult was a Leftist organization.