The 2016 Massachusetts ballot included a referendum - Question 2 - proposing to eliminate the states current "cap" on the number of charter schools permitted. Question 2 was the first ballot referendum in the country about charter school expansion. Backers of the ballot measure saw this as an important "test case" to champion school choice. Ten months before the election, the pro-expansion side boasted many advantages, including $18 million, endorsements from the governor and the two largest newspapers in the state, and a 25-point lead in the polls. Yet, despite getting outspent by nearly $11 million in what became the most expensive ballot referendum in Massachusetts history, the opposition secured a decisive victory. My study asks what shaped this unexpected outcome. I argue two factors were decisive. First, the No on 2 side engaged teachers' union members - namely classroom educators - to become what I call everyday spokespeople, while the Yes on 2 campaign relied on advertising and paid canvassers. Second, although the mostly White teachers and their unions were vulnerable to criticisms framing their stance as racist and self-interested, they were able to build an interracial coalition, what I call a racial resource, that neutralized the "civil rights issue of our time" argument that pro-charter expansion advocates wanted to feature. I argue that No on 2 was able to develop and deploy more authentic and trusted racial resources in a more ideologically coherent way than the Yes on 2 campaign, which opted for an interracial advertising strategy funded by White elites.