Late last month, the National School Boards Association, a group that has represented school boards since 1940, made an unusual request of the federal government. “Threats of violence and acts of intimidation” directed at school officials were escalating across the country, the association said, and it asked the Biden Administration to investigate and use “existing statutes, executive authority,” and “other extraordinary measures” to combat a phenomenon it likened to domestic terrorism. On Monday, Attorney General Merrick Garland decried such incidents and ordered the F.B.I. to monitor them.

If you want some evidence of what the association and Garland were responding to, it’s easy to find in YouTube videos, and local news reports by the score—protesters fairly vibrating with January 6th energy as they disrupt school-board meetings, raging against mask mandates and other covid precautions, or that favorite spectral horror, critical race theory. (The N.S.B.A. letter wearily explains that “critical race theory is not taught in public schools and remains a complex law school and graduate school subject well beyond the scope of a K-12 class.”) Since the summer, these confrontations have become social-media staples, familiar enough for “Saturday Night Live” to do a spot-on parody of them for its season opener.

After a school-board meeting in Williamson County, Tennessee, a group of protesters surrounded a doctor who had testified in favor of students wearing masks, shouting,“You’re a child abuser,” “We know who you are,” and “You’ll never be allowed in public again.” In San Diego County, California, in September, anti-mask protesters forced their way into a school-board meeting and tried to swear themselves in as the new, unelected members. At a chaotic meeting in Buncombe, North Carolina, parents opposed to a mask mandate announced that they, too, had “overthrown” the school board. Members of the far-right Proud Boys showed up twice, faces covered, at school-board meetings in Nashua, New Hampshire; in Vancouver, Oregon, Proud Boys gained access to school grounds during anti-mask protests, leading to a lockdown of the schools. At a Loudoun County, Virginia, school-board meeting, which was considering the district’s policies for transgender students and racial equity, riled-up conservatives got so out of hand that the board chair halted the proceedings while the police cleared the room.

Writing in the Washington Post recently, Adam Laats, a professor of education at Binghamton University SUNY, suggested that these outbursts can “be understood as a politics of petulance. At moments when American culture has taken some progressive turn, conservatives have consistently blamed a single culprit for indoctrinating vulnerable youth with radical ideas: public schools.” The attraction of school-board meetings for such displays of frustration, Laats told me, is “that they are generally so accessible; there’s an open-mike aspect to them.”

Laats has written a book, “The Other School Reformers,” about the history of conservative agitation around public schools, which makes clear that there are precedents for the current eruptions. Perhaps the most salient is a parents’ uprising in Kanawha County, West Virginia, in 1974, against the adoption of a new series of literature textbooks that some people thought promoted anti-American sentiments. The protests evolved into a boycott of the district’s schools, attracting national media attention, and soon turned violent. Textbook opponents shot up empty school buses and classrooms, bombed the school-board building, and threw rocks at parents who were still taking their children to school. Though the textbooks were ultimately adopted, and the rage over them seemed to fade, the West Virginia parents’ revolt had a wider impact on social conservatism. It helped launch the modern homeschooling and Christian-school movements, Heath Brown, a political scientist at John Jay College who has studied homeschooling activists, says, because some parents peeled away from public schools altogether in the aftermath of the boycott. The West Virginia textbook battle propelled the Heritage Foundation, then a small upstart organization, now a conservative-policy behemoth, onto the national stage. Heritage, Laats shows, provided free legal counsel to the protesters and drew connections between their local crusade and the broader defense of parental rights and liberties.