A couple of links discussing the topic that provide some insight. They both follow the shooting at the Congressional baseball practice.
https://www.thenation.com/article/why-does-the-far-right-hold-a-near-monopoly-on-political-violence/
A couple of quotes:
Which raises an important question: If red and blue America fear and loathe one another equally, and a similar number believe that political violence is acceptable, then why is there so much more of it on the fringes of the right?
Part of the answer lies in a clear difference between right and left: For the past 40 years, Republicans, parroting the gun-rights movement, have actively promoted the idea that firearms are a vital bulwark against government tyranny.
The belief that democratic government rests on the Second Amendment has become widespread among Americans; one
poll found that about two-thirds believe that “their constitutional right to own a gun was intended to ensure their freedom.” But Robert Spitzer, a political scientist at SUNY Cortland and the author of several books on the politics of guns, says that’s a modern idea. While “there’s a long tradition of some in America feeling deeply mistrustful of our government—and there have been incidents throughout our history where people took up arms against the government—the more specific idea that there’s a right to rebel, or that somehow you can keep the government under control by taking up weapons, found its first serious expression in a law review article published in 1960. And the idea really took hold among a subset of Americans and a subset of gun owners, who argue to this day that this was part of the purpose of the Second Amendment. They talk about the Minutemen and the Revolutionary War and the Declaration of Independence. The idea really took hold in the 1970s and 1980s when the NRA itself began to use this same kind of rhetoric.”
It’s also infused right-wing politics beyond the gun lobby. Watering the “tree of liberty” with the “blood of patriots and tyrants” is a common theme in Tea Party circles, where the Gadsden flag—don’t tread on me!—and loose talk of revolution blend seamlessly with mainstream anti-tax ideology and disdain for liberals. While a handful of Democrats competing in red states have run ads featuring them firing weapons, it’s become almost universal in Republican campaigns, where it not only marks a candidate’s opposition to gun-safety legislation but also signals that he or she is ready to wage war against the Washington establishment.
War as a metaphor for politics isn’t limited to the right, but it has become a constant in conservative discourse. “The first shots of the second American civil war have already been fired,”
said Alex Jones earlier this month. “We are in a clear-cut cultural civil war,”
according to Newt Gingrich. Pat Buchanan
offered that we’re “approaching something of a civil war,” and said that it’s time for Trump to “burn down the Bastille.” “You ain’t got any idea of the war that’s raging outside the four walls of the church,” religious-right activist
Dave Daubenmire told a crowd of antigay protesters last weekend. “Don’t you understand what’s going on? Don’t you know it’s a war? Don’t you know they want your children? Don’t you understand that those same people singing ‘Jesus loves you this I know’ want to kill us?” Then there’s the quasi-apocalyptic prepper mentality, which holds that we’re on the brink of social collapse so you’d better buy gold and stock up on ammo for when the sh#t inevitably hits the fan.
Nathan Kalmoe says that there’s “an important distinction to make between people who have more conventional views, versus people who have much more extreme views.” He thinks that, whether on the left or the right, those who are at least somewhat close to the mainstream “probably have a greater commitment to nonviolent approaches to politics and are socialized into nonviolent norms of how participation is supposed to work.” But on the right those lines have become blurred in recent years—Glenn Beck’s goldbuggery, the ravings of the “alt-right” and the Minutemen theory of gun rights have all become features of the larger conservative landscape, even if they’re not
quite mainstream.
Kalmoe says that rhetoric alone “isn’t the main cause of political violence, but violent language and vilifying opponents can nudge people in ways that make them think and act more aggressively in politics.” He conducted an experiment that first measured subjects’ aggressive personality traits. Then he exposed them to two imaginary political ads, one that employed mildly violent political rhetoric and one that used neutral language, and he found that those subjects who had already displayed a penchant for aggressive behavior were far more likely to support political violence after being exposed to the violent rhetoric. So it’s not that violent rhetoric
causes real-world violence so much as it can “make people who behave aggressively in real-life more likely to endorse violence against political leaders.”
Liberals believe that mature institutions and the separation of powers are what keep tyranny at bay, not an AR-15. If James Hodgkinson looked around himself and saw a president who acts as if he’s above the law and a Congress that’s working in the dark to strip away health insurance from millions of people to finance tax cuts for the wealthy but is unwilling to perform its oversight duties, and decided that he would stand up to tyranny with an assault rifle, he would have taken a theme that’s exceedingly common on the right to its bloody logical conclusion.
http://www.npr.org/2017/06/16/533255619/fact-check-is-left-wing-violence-rising
Quoted in part:
The idea that some on the far left are openly condoning violence is a red flag for extremist group monitors.
"This is a dangerous game; people are going to die. No one's died yet, but it's just a matter of time," says J.J. McNabb, an expert on political extremism at George Washington University.
McNabb says white supremacists and neo-Nazis are widely condemned — and deservedly — for their violent tendencies. But she says the Antifa shouldn't get a pass on their violence just because they oppose white supremacists.
"These guys are odious, [but] attack them with words. Don't come in with sticks and nails in them," she says.
Antifa are not new. They're a latter-day version of the anarchists and "black bloc" groups who, over the years, have often challenged police and broken windows during May Day protests in Seattle and Portland. Their membership is hard to track, but it appears to be expanding beyond the West Coast. They are also embracing other leftist causes beyond just fighting white supremacists.
Still, their numbers are tiny in relation to the mainstream political left. And, say experts, it's misleading for right-wing groups to suggest that the Antifa are more violent than right-wing extremists.
"The far left is very active in the United States, but it hasn't been particularly violent for some time," says Mark Pitcavage, a senior research fellow at the Anti-Defamation League's Center on Extremism.
He says the numbers between the groups don't compare.
"In the past 10 years when you look at murders committed by domestic extremists in the United States of all types, right-wing extremists are responsible for about 74 percent of those murders," Pitcavage says.
You have to go back to the 1970s to find the last big cycle of far-left extremism in the U.S. Both Pitcavage and McNabb say we have been in a predominantly far-right extremist cycle since the 1990s — the abortion clinic bombings and Oklahoma City, for example. And, more recently, racially motivated attacks such as the one at a Sikh temple in Wisconsin, the mass shooting at a black church in Charleston, S.C., and last month's stabbings on a commuter train in Portland.
Still, Pitcavage says Wednesday's shooting attack on Republican members of Congress is a warning sign. He is especially concerned because the shooter apparently was not particularly extreme in his political ideas; his views were seemingly in the mainstream left.
