Republicans hope that concerns about critical race theory can help them in the midterm elections. The issue has torn apart one Wisconsin suburb.Little more than a year ago, Scarlett Johnson was a stay-at-home mother, devoted to chauffeuring her children to school and supervising their homework.That was before the school system in her affluent Milwaukee suburb posted a video about privilege and race that “jarred me to my core,” she said.“There was this pyramid — where are you on the scale of being a racist,” Ms. Johnson said. “I couldn’t understand why this was recommended to parents and stakeholders.”The video solidified Ms. Johnson’s concerns, she said, that the district, Mequon-Thiensville, was “prioritizing race and identity” and introducing critical race theory, an academic framework used in higher education that views racism as ingrained in law and other modern institutions.Since then, Ms. Johnson’s life has taken a dramatic turn — a “180,” she calls it. She became an activist, orchestrating a recall of her local school board. Then, she became a board candidate herself.Republicans in Wisconsin have embraced her. She’s appeared on panels and podcasts, and attracted help from representatives of two well-funded conservative groups. When Rebecca Kleefisch, the former Republican lieutenant governor, announced her campaign for governor, Ms. Johnson joined her onstage.Ms. Kleefisch’s campaign has since helped organize door-to-door outreach for Ms. Johnson and three other school board candidates.Ms. Johnson’s rapid transformation into a sought-after activist illustrates how Republicans are using fears of critical race theory to drive school board recalls and energize conservatives, hoping to lay groundwork for the 2022 midterm elections.“Midterm elections everywhere, but particularly in Wisconsin, are pretty dependent on voter turnout as opposed to persuasion,” said Sachin Chheda, a Democratic political consultant based in Milwaukee. “This is one of the issues that could do it.”Scarlett Johnson in Mequon, Wis., in September. Ms. Johnson is an activist against teaching critical race theory in schools, orchestrating a recall of her local school board.Carlos Javier Ortiz for The New York TimesBallotpedia, a nonpartisan political encyclopedia, said it had tracked 80 school board recall efforts against 207 board members in 2021 — the highest number since it began tracking in 2010.Education leaders, including the National School Boards Association, deny that there is any critical race theory being taught in K-12 schools.“Critical race theory is not taught in our district, period,” said Wendy Francour, a school board member in Ms. Johnson’s district now facing recall.Teachers’ unions and some educators say that some of the efforts being labeled critical race theory by critics are simply efforts to teach history and civics.“We should call this controversy what it is — a scare campaign cooked up by G.O.P. operatives” and others to “limit our students’ education and understanding of historical and current events,” said Randi Weingarten, the president of the American Federation of Teachers.But Republicans say critical race theory has invaded classrooms and erroneously casts all white people as oppressors and all Black people as victims. The issue has become a major rallying point for Republicans from Florida to Idaho, where state lawmakers have moved to ban it.In July, Glenn Youngkin, the Republican nominee for governor of Virginia, promised to abolish critical race theory on “Day 1” in office. In Florida, Gov. Ron DeSantis, facing re-election next year, said recently, “I want to make sure people are not supporting critical race theory.” And in Arizona, Blake Masters, a Republican hoping to unseat Senator Mark Kelly in 2022, has repeatedly slammed critical race theory as “anti-white racism.”In some places, the tone of school board opponents has become angry and threatening, so much so that the National School Boards Association asked President Biden for federal law enforcement protection.Few places will be more closely watched in the midterm elections than Wisconsin, a swing state that Mr. Biden won by just over 20,600 votes and where Republicans would like to retain control of the Senate seat currently held by Ron Johnson, as well as to defeat Gov. Tony Evers, a Democrat.To succeed, Republicans must solidify support in suburban Milwaukee, an area of historical strength for the party. Recently, though, Democrats have made inroads in Ozaukee County, and particularly its largest city, Mequon, a mostly white enclave north of Milwaukee. President Donald J. Trump won the city last year with only 50.2 percent of the vote — a poor showing that contributed to his Wisconsin defeat.Now, with midterms on the horizon, prospective statewide candidates — including Ms. Kleefisch, Senator Johnson and the relative political newcomer Kevin Nicholson — have emphasized their opposition to critical race theory.Senator Johnson, who has not announced whether he will seek re-election, has talked about the importance of local elections as a prelude to next year’s midterms. He recently urged constituents to “take back our school boards, our county boards, our city councils.”Traditionally, school board elections in Wisconsin have been nonpartisan, but a political action committee associated with Ms. Kleefisch — Rebecca Kleefisch PAC — recently contributed to about 30 school board candidates around the state, including one elected last spring in Mequon.“The fact that this is being politically driven is heartbreaking,” said Chris Schultz, a retired teacher in Mequon and one of the four board members facing recall.Ms. Schultz relinquished her Republican Party membership when she joined the board. “I believe school boards need to be nonpolitical,” she said. “Our student welfare cannot be a political football.”Now, she thinks, that’s over. “The Republican Party has kind of decided that they want to not just have their say on the school board but determine the direction of school districts,” she said.Rebecca Kleefisch, Wisconsin’s former lieutenant governor, announces her candidacy for governor in September. Last week, volunteers from Ms. Kleefisch’s campaign organized outreach for Ms. Johnson’s school board candidacy.John Hart/Wisconsin State Journal, via Associated PressAgainst this political backdrop, Ms. Johnson, who calls herself a lifelong conservative, is waging her own battle in the district that serves 3,700 students. Ms. Johnson, 47, has five children, ranging in age from 10 to 22. Her two oldest children graduated from Mequon-Thiensville’s vaunted Homestead High School. Complaining about a decline in the system’s quality, she said she chose to send her younger children to private schools.Ms. Johnson first got interested in school board politics in August 2020, after a decision to delay in-person classes because of an increase in Covid-19 cases. Angered over the delay, Ms. Johnson protested with more than 100 people outside school district headquarters.“Virtual learning is not possible for the majority of parents that work,” Ms. Johnson told a reporter.The next day, protesters gathered outside the business of Akram Khan, a school board member who runs a private tutoring center.“There was this narrative that I, as a board member, elected to close the schools down because it would directly benefit my pocketbook, which is the farthest thing from the truth,” Mr. Khan said.He shut down his business temporarily as a result of the protests and is now facing recall.Things got worse. Protesters showed up outside the home of the district superintendent; relationships among neighbors began to fray. School board meetings, formerly dull affairs, dragged on for hours, with comments taking on a nasty and divisive tone.“We’ve been called Marxist flunkies,” Ms. Francour said. “We have police attending the meetings now.”Akram Khan is facing a school board recall.Carlos Javier Ortiz for The New York TimesWendy Francour, who is facing a recall, said school board meetings have gotten divisive: “We have police attending the meetings now.”Carlos Javier Ortiz for The New York TimesAnger grew over masks, test scores and the hourlong video the school system posted about race, one of two that Ms. Francour said were offered because parents had asked what to tell their children about George Floyd’s murder in Minneapolis.Led by two consultants, the optional online seminar for parents included a discussion of the spectrum of racism — from lynching to indifference to abolitionism — and tips on how to become “anti-racist” through acts such as speaking up against bias and socializing with people of color. It ended with news clips about Mr. Floyd’s death.Ms. Johnson, who grew up poor in Milwaukee, the daughter of a Puerto Rican teenage mother and a father who had brushes with the law, said the video ran counter to her belief that people were not limited by their background or skin color.“For me the sky was the limit,” Ms. Johnson said in July on “Fact Check,” a podcast hosted by Bill Feehan, a staunch Trump supporter and the La Crosse County Republican Party chairman.The Wisconsin Democratic Party recently provided The Milwaukee Journal Sentinel with deleted tweets by Ms. Johnson expressing nonchalance about the threat of white supremacy and accusing Planned Parenthood of racism.Spurred partly by the video, Ms. Johnson began leading an effort, Recall MTSD.com, to recall four of seven board members. Petitions were available at local businesses, including a shooting range owned by a Republican activist, Cheryle Rebholz.While the recall group insists theirs is a grass-roots effort, representatives of two conservative nonprofit organizations turned up to help.Amber Schroeder, left, and Ms. Johnson dropping off recall petitions in Mequon in August.Morry Gash/Associated PressOne of them, the Wisconsin Institute for Law & Liberty, is funded by the Bradley Foundation, known for promoting school choice and challenging election rules across the country.The organization stepped in to help Ms. Johnson’s group by threatening legal action against the city of Mequon when it tried to remove banners, placed on public property, that promoted the recall.Another volunteer with a high profile in conservative circles was Matt Batzel, executive director of American Majority, a national group that trains political candidates. Mr. Batzel’s organization once published a primer on how to “flip” your school board, citing its role overturning a liberal board in Kenosha, Wis.Mequon’s recall election is Nov. 2. One candidate is Ms. Rebholz, the shooting range owner, who wrote an essay arguing that, “If the Biden-Harris team wins in November, Americans won’t be safe.”Meanwhile, Ms. Johnson is branching out.She serves as a state leader for No Left Turn in Education, an organization against critical race theory, and has recently been named to a campaign advisory board for Ms. Kleefisch.She spoke at a Milwaukee event last month. The topic: “What is Critical Race Theory and How to Fight It.” More