When the Chicago Teachers Union (CTU) reform caucus, the Caucus of Rank-and-File Educators (CORE), started out in 2008, we were like an exhibition team entering a league where one powerhouse team dominated the landscape for over half a century. We were serious underdogs, a ragtag team of teacher activists running against a deeply entrenched union leadership that had refused to wage a real fight against the forces of free-market education reformers that were ravaging our public schools. Jesse Sharkey, the CTU’s current president and then delegate of Senn High School, began to strike up conversations with Karen Lewis, a delegate from King College Prep High School. Jesse recruited Karen to CORE — who proceeded to change the course of history for the CTU, the city, and the country.

Karen, whose death was announced on Monday at age sixty-seven, added the gravitas of a Chicago Public Schools (CPS) veteran to team CORE. She graduated from Kenwood Academy High School, a famous CPS school, grew up in the black middle class on the South Side, daughter of two CPS teachers. As a result, she knew the system and the city better than any of us. Karen and her husband, John Lewis, met at Lane Tech College Prep High School as black teachers sent to integrate a school with a predominantly white staff under a desegregation decree from the district. At Lane, she cut her teeth as a union delegate, breaking ranks with the union’s incumbent leadership and joining the Executive Board after Debby Lynch unexpectedly won the union presidency in 2001 as the head of a dissident caucus, Proactive Teachers, for the first time in the union’s seventy-year history.

Karen was by all accounts a renaissance woman: a thespian, comedian, scientist, close reader of the Talmud, former doctor-in-training, chemistry teacher, pianist, linguist, a lover, and a fighter. On more than one occasion, Karen told the story of taking off her earrings and lathering on some vaseline to brawl with our class enemies. Subtle, she was not. Inspiring, without a doubt.

Jesse lovingly called Karen “low-down” for her blunt and unvarnished truth talk. At the meeting of the union’s House of Delegates, its governing body made up of its members, this week after Karen’s death, Jesse noted that she “taught us to see our own power and believed in the purpose of public education and the justice in it.” At the same meeting, Stacy Davis Gates, the CTU vice president, celebrated Karen for “prioritizing the hearts and humanity of our members.”

Karen had an uncanny ability to fill a room with both laughter and radical politics, a manner that was initially vilified but later celebrated by the news media. Her aphoristic, bombastic way of painting our class enemies as out-of-touch corporate hacks was genius political theater. And she had a tremendous ability to turn the tide from the onslaught of negative press we faced upon taking union office in 2010 to using it as a tool for communicating to the broader public, parents, and communities of color in particular.

Whether calling out Rahm Emanuel as the “murder mayor” for his attacks on the city’s working class, Republican Illinois governor Bruce Rauner as an adherent of ISIS for his dismantling of social services, or indicting the whole district for reifying “educational apartheid,” her rhetoric cut deeply without apology while lambasting the racial and economic disparities in our city with precision. She chose Stephanie Gadlin to be the CTU’s communications director precisely because of her ability to advance social and racial justice demands with media strategy.

In some ways, Karen was an unlikely partner in a left-led project for union revival. But she was uniquely predisposed to unite the disparate forces within our movement. While interested in rooting out the corrupt machine tendencies within the union, she was not a self-described leftist. On many occasions, Karen would ask me about her politics, “What am I again, Jackson?” while smirking playfully. I would struggle to answer but often said something like “a blend of social democrat with black nationalist.” My answer would always tickle her because though she never saw herself as a Marxist, she also did not subscribe to any other particular ideology.

Either way, she loved it when the CTU’s enemies would call us “a socialist conspiracy.” Her political instincts were mostly populist and rooted in the experience of black, working-class Chicago.

As a leader in CORE and our first co-chair (I had the privilege to serve alongside her), Karen was not just our primary spokesperson, but instrumental in constructing the democratic norms and structures key to transforming both CORE and the CTU into an organizing force. She got her hands dirty and was not aloof. Karen wrote the bylaws and constitution for the caucus, led one of our first study groups on Naomi Klein’s The Shock Doctrine, and chaired CORE’s coalition table with community groups and members of Local School Councils, the governing bodies of neighborhood schools made up of community members, that led the resistance to school closings and the school privatization plan known as Renaissance 2010.

In very significant ways, Karen’s leadership method was forged in a baptism by fire in the first moments after we were elected to the union’s leadership in 2010. CPS CEO Ron Huberman and Mayor Richard M. Daley immediately came after us, claiming a budget crisis that demanded we forfeit scheduled salary increases — or suffer four-thousand-plus layoffs. We refused concessions and absorbed a much smaller number of layoffs.

Karen noted the bluff for future bargaining strategy and the importance of standing our ground. We were subsequently hit by SB-7, a bill in the Illinois State Legislature fueled by enormous political donations and ad buys by astroturf neoliberal reform groups like Stand for Children (or as Karen called them, “Stand on Children”) and Democrats for Education Reform. These groups were funded by the biggest corporations in town who led the Civic Committee of the Commercial Club of Chicago and were the architects for the majority of attacks on public education over the previous thirty years.

The bill stripped the union of key aspects of our bargaining power and made us the only union in the state that must get 75 percent of our active membership to approve a strike vote in order to authorize strike action. After this attack, Karen picked herself off the mat and set about envisioning how the union could alter the political landscape to prevent the future and imminent destruction of our union.

Part of her re-imagination of the union involved initiating the CTU’s first organizing department, first research department, and a reconfiguration of staff that allowed greater resources for member outreach, coalition work with community partners, and strike preparation. Additionally, it was Karen’s vision, along with the political instincts of Stacy Davis Gates, Brandon Johnson, and Matthew Luskin that became a template for new political formations like United Working Families that soon led to teachers winning elections at all levels of city, state, and county government.

Our community coalition, the Grassroots Education Movement, seeded the wave of socialist and left aldermen storming Chicago’s city council — including Byron Sigcho-Lopez, who worked with GEM while executive director of the Pilsen Alliance, and Jeanette Taylor, a leader in the education justice work of the Kenwood Oakland Community Organization. According to Jeanette, “Karen, actually brought the families, parents, and communities into the union.”

Karen never wanted credit for the gargantuan collective effort required by thousands of member leaders, community allies, organizers, and rank-and-file activists to revive the CTU. She always recognized that it takes a village. But it was her life force that helped launched the zeitgeist of a new militant teachers’ movement that has not stopped growing since she helped spark it. We are all deeply saddened that she is gone. She will, in the words of Alderwoman Taylor, “rest in red.”