The assassination of conservative activist Charlie Kirk is the latest in a growing list of incidents of political violence. There have been 150 politically motivated attacks just this year, and a 2000% increase in targeted violent plots over the past two decades. What explains this surge in political violence? Extremism expert Cynthia Miller-Idriss confirms that this is “the worst moment of political violence since the 1970s,” adding, "We are in an era of mass shootings." She argues that rising polarization and “the common thread" of misogyny links many recent attacks. Miller-Idriss is the founding director of the Polarization and Extremism Research Innovation Lab at American University, where she is also a professor in the School of Public Affairs and the School of Education. Her latest book is “Man Up: The New Misogyny and the Rise of Violent Extremism.” She is an MSNBC columnist and regular commentator who appears frequently on CNN, PBS and other news outlets. President Donald Trump has vowed to mount a government assault on “the left” in response to Kirk’s assassination. But a recent study by the Center for Strategic and International Studies shows that despite a small uptick in “left-wing” violence this year, ”right-wing” terrorism has far exceeded all other forms of political violence in the number of fatalities and attacks in the past decade. Miller-Idriss contends that most mass shooters, terrorists and violent extremists have two things in common: Nearly all are men, and they are almost always “virulent misogynists, homophobes or transphobes.” She says that the media — herself included — have long overlooked this link between political violence and misogyny. The U.S. now averages more than one mass shooting per day. “Virtually every mass shooter in the U.S. has a history of gender-based violence in some way,” with 60% of them having documented histories of domestic violence or “stalking, harassment, rape threats, cyber porn, revenge porn, sexual assault, rape, anti-LGBTQ violence,” Miller-Idriss said. “Even when the targets are not very clearly women or the LGBTQ community … gender or homophobia really significantly play a role.” Miller-Idriss highlighted two factors that make this era of political violence unique — the proliferation of guns and online communities that traffic in hate. “We have a lot of shootings that don't seem to have any ideological motivation at all but are really at the hands of extraordinarily online young people … who spend a lot of time in online spaces, in gaming spaces, in very meme-driven, irony laden spaces,” she said. Attackers “are kind of communicating, almost in a way that may be detached from reality, with online communities as part of the attack.” Shooters are “not just highly online but expressing a lot of online misogyny and gender-based harms or harassing teenage girls online,” she said. Miller-Idriss said that even “everyday forms of misogyny” that she and other women face are linked to more extreme forms. She said she observed that in the hate mail that she receives that there was “a very clear pattern of containment, that what they wanted was for me to not be front and center.” “There's some sort of anger there about a person, a woman, being in a public space at all, and it makes you realize that phrases like ‘lock her up,’ ‘send them back,’ ‘get back in the closet,’ ‘get back in the kitchen’ (are) containment metaphors (that) are very, very common in everyday life directed toward women or LGBTQ folks who are seen as being too public or too flamboyant or too out,” she said. Everyday misogyny “can evolve into a trajectory in which some young men are conditioned through online influencers to believe that they have lost their rightful place, that women belong in a more submissive role,” Miller-Idriss said. “Some men are so easily mobilized to anger if they're denied what they think they're entitled to (and) that might escalate eventually into rage in a more public way,” she said. Miller-Idriss and her colleagues at the Polarization and Extremism Research Innovation Lab work with young people to “off-ramp” violent online hate. “If you start to recognize that part of the problem of mass shootings and mass violence is rooted in very everyday harms, then you can take action on those everyday harms,” she said. “It should be an empowering message to say, ‘Let's have a conversation about what this looks like, and let's have a conversation about the experience of boys compared to girls.’”