Nicole Hannah-Jones, a staff writer for the New York Times magazine, aptly describes the perilous condition of public education, as the privatization movement moves in to kill public education. The very idea that schools should operate like businesses and that families are “consumers,” eats away at the promise of public education.

In the days leading up to and after Betsy DeVos’s confirmation as secretary of education, a hashtag spread across Twitter: #publicschoolproud. Parents and teachers tweeted photos of their kids studying, performing, eating lunch together. People of all races tweeted about how public schools changed them, saved them, helped them succeed. The hashtag and storytelling was a rebuttal to DeVos, who called traditional public schools a “dead end” and who bankrolled efforts to pass reforms in Michigan, her home state, that would funnel public funds in the form of vouchers into religious and privately operated schools and encouraged the proliferation of for-profit charter schools. The tweets railed against DeVos’s labeling of public schools as an industry that needed to adopt the free-market principles of competition and choice. #Publicschoolproud was seen as an effort to show that public schools still mattered.

But the enthusiastic defense obscured a larger truth: We began moving away from the “public” in public education a long time ago. In fact, treating public schools like a business these days is largely a matter of fact in many places. Parents have pushed for school-choice policies that encourage shopping for public schools that they hope will give their children an advantage and for the expansion of charter schools that are run by private organizations with public funds. Large numbers of public schools have selective admissions policies that keep most kids out. And parents pay top dollar to buy into neighborhoods zoned to “good” public schools that can be as exclusive as private ones. The glaring reality is, whether we are talking about schools or other institutions, it seems as if we have forgotten what “public” really means.

Public schools were supported by all, because they were for the benefit of all, whether or not they used the schools themselves, whether or not they had children.

Early on, it was this investment in public institutions that set America apart from other countries. Public hospitals ensured that even the indigent received good medical care — health problems for some could turn into epidemics for us all. Public parks gave access to the great outdoors not just to the wealthy who could retreat to their country estates but to the masses in the nation’s cities. Every state invested in public universities. Public schools became widespread in the 1800s, not to provide an advantage for particular individuals but with the understanding that shuffling the wealthy and working class together (though not black Americans and other racial minorities) would create a common sense of citizenship and national identity, that it would tie together the fates of the haves and the have-nots and that doing so benefited the nation. A sense of the public good was a unifying force because it meant that the rich and the poor, the powerful and the meek, shared the spoils — as well as the burdens — of this messy democracy.

The New Deal fostered a strong public sector, but it also was ridiculed and condemned by a small minority who resented the effort to include everyone in good works. This minority sowed the seeds of the libertarian, free-market, anti-government movement that is now controlling the federal government and many states.

She reminds us that the movement away from public schools began with segregationists who wanted to keep their all-white schools. Betsy DeVos speaks for them when she lauds school choice.

Even when they fail, the guiding values of public institutions, of the public good, are equality and justice. The guiding value of the free market is profit. The for-profit charters DeVos helped expand have not provided an appreciably better education for Detroit’s children, yet they’ve continued to expand because they are profitable — or as Tom Watkins, Michigan’s former education superintendent, said, “In a number of cases, people are making a boatload of money, and the kids aren’t getting educated.”

Democracy works only if those who have the money or the power to opt out of public things choose instead to opt in for the common good. It’s called a social contract, and we’ve seen what happens in cities where the social contract is broken: White residents vote against tax hikes to fund schools where they don’t send their children, parks go untended and libraries shutter because affluent people feel no obligation to help pay for things they don’t need. “The existence of public things — to meet each other, to fight about, to pay for together, to enjoy, to complain about — this is absolutely indispensable to democratic life,” Honig says.

If there is hope for a renewal of our belief in public institutions and a common good, it may reside in the public schools. Nine of 10 children attend one, a rate of participation that few, if any, other public bodies can claim, and schools, as segregated as many are, remain one of the few institutions where Americans of different classes and races mix. The vast multiracial, socioeconomically diverse defense of public schools that DeVos set off may show that we have not yet given up on the ideals of the public — and on ourselves.

Make no mistake: Betsy DeVos is a dedicated enemy of public schools. She threatens to destroy the educational system that produced the most powerful economy on earth. She must be resisted at every turn.