Undocumented immigrants and permanent legal residents in San Francisco will have the chance to cast their ballots for the local school board on November 6. This newly established right is the result of a ballot initiative approved by 54 percent of voters in 2016. (Past referendums failed in 2004 and 2010.) Advocates made the case that noncitizen voting would increase parental involvement in schools and that expanding democracy to marginalized groups would help fortify civic life.

But Donald Trump was also elected president in 2016, throwing this hard-fought victory into a tailspin. “The timing is unfortunate, but we’re dealing with what we have,” said Norma Garcia, the director of policy and advocacy at the Mission Economic Development Agency, a community-based organization that helped to pass San Francisco’s noncitizen voting. Activists have been working to assuage panic—but the fear is real. To register, noncitizens have to provide their address and date of birth, and are explicitly warned on their forms that any information they provide to the Department of Elections may be obtained by Immigration and Customs Enforcement “and other agencies, organizations and individuals.” Immigrants are being encouraged to consult with an attorney before signing up.

Hong Mei Pang, the director of advocacy at Chinese for Affirmative Action, another San Francisco–based organization that helped pass the voting-rights measure, said they’ve been educating immigrants and stressing that noncitizens shouldn’t feel pressured to vote. “The cruelty of this particular administration is it’s forcing immigrants to make impossible, hard choices,” she said. “They’re manufacturing these dilemmas, and one should never have to choose between their right to health, dignity, and to be a free person who can exercise their political voice.” As of October 30, just 52 noncitizens had registered with the San Francisco Department of Elections.

At the same time, other cities have started conversations of their own around noncitizen voting. Montpelier, a liberal Vermont city of just under 8,000 people, held a public forum this past spring to explore the idea, and will have a referendum on its ballot this November. Boston leaders also held a public hearing this past summer, led by the City Council president who said noncitizen voting could be a way to signal solidarity with immigrants in the age of Trump.

Meanwhile, a backlash has been brewing. In July, Doug Ose, a Republican from California who served in the House of Representatives, submitted a ballot initiative to ban noncitizen voting statewide—saying San Francisco’s new right convinced him to take action. (He will need to collect 365,880 valid signatures to get his measure approved for California’s 2020 ballot.) Two months later in Washington, DC, Representative Kevin McCarthy (R-CA) introduced a non-binding resolution condemning noncitizen voting, with the decree specifically citing San Francisco. It passed with 279 votes in favor. “There’s a new movement that’s going on around the country, allowing illegals to vote in our elections, disenfranchising Americans,” said McCarthy, who is expected to become speaker of the House when Paul Ryan steps down from the job later this year.

The story of voting rights in the United States is typically understood as a slow and steady march toward universal suffrage—but noncitizen voting stands as a major exception to this narrative.

During the colonial period and after the American Revolution, white male property owners—regardless of citizenship—were allowed to vote. Noncitizen voting was common at the local, state, and even federal levels for the country’s first 150 years. It was seen “as a means to train newcomer white Christian men to be good neighbors and promote active participation in the life of their new adoptive homes before their eventual naturalization,” write San Francisco–based scholars Ron Hayduk and Kathleen Coll who have studied the history. “In frontier states, it was also a way to lure new white male immigrants to permanently occupy Native lands.” It was not so much a substitution for citizenship as a pathway toward it.

Yet hostility toward foreigners increased during and after the War of 1812, and a few states began to restrict noncitizen voting. The surge of Irish immigrants, who generally opposed slavery, was one factor fueling the xenophobia. In 1861, the Confederate Constitution carved out a prohibition for persons “of foreign birth” from voting, although the practice continued and even expanded in the next few decades. But in the years leading up to World War I, a new wave of nativist sentiment prompted states to eliminate noncitizen voting, with Arkansas being the final state to end the practice in 1926.

In 1993, Jamie Raskin—now a Democratic member of Congress from Maryland and back then an American University law professor—authored a legal paper, where he argued “the current blanket exclusion of noncitizens from the ballot is neither constitutionally required nor historically normal.” Three years later, however, Congress passed the Illegal Immigration Reform and Immigrant Responsibility Act, banning noncitizens from voting in federal elections. But on the state and local level, noncitizen voting can still be legally authorized today.

The first city to bring back noncitizen voting was New York City in 1968. As a concession during the city’s fight over “community control” of schools—a movement to hold schools accountable by empowering parent representatives—New York granted its noncitizens the right to vote in school-board elections. Noncitizens voted in these elections up until 2002, when the city switched to mayoral control and abolished its elected school board.

Since 1989 Chicago has also allowed noncitizens to vote and serve on its school councils, bodies that approve how school resources are allocated, develop and monitor school-improvement plans, and select a school’s principal. Aside from Chicago and San Francisco, 10 other cities allow noncitizen voting, and they are all in Maryland. This is partly because Maryland cities can pass laws about noncitizen voting and enact them without state approval. While four Massachusetts cities—Amherst, Brookline, Cambridge, and Newton—have all also approved noncitizen voting, their local laws have never taken effect because the Massachusetts legislature never gave them the necessary go-ahead.

But why has this history gone so under the radar? “It’s an obscure piece of history, but when you realize how extensive and widespread it was, it is really surprising that it’s not more widely known,” Hayduk said. He guessed that one reason is because of the radical implications of it’s being on the table. “As the immigrant-voting-rights people put it, ‘It could give you ideas,’” he said. Once you accept the idea that democracy is strengthened by allowing noncitizens to weigh in on local elections, excluding those same people from state and federal contests becomes harder to defend.

Activists in San Francisco have looked to Takoma Park, a Maryland suburb outside of Washington, DC, that has successfully implemented noncitizen voting for the past quarter-century. In 1992 the city adopted a charter resolution that removed its citizenship requirement for voting and holding local office. Takoma Park was also one of the first sanctuary cities in the country, passing legislation in 1985 to protect refugees arriving from Nicaragua and El Salvador. In a city of 18,000, 347 noncitizens registered to vote in 2017.

Like San Francisco, Takoma Park’s voter-registration form for noncitizens includes a warning: “Please be aware that registering to vote or voting in jurisdictions other than Takoma Park may result in adverse immigration consequences for a non-U.S. citizen.” Jessie Carpenter, Takoma Park’s city clerk, said she liked the more explicit language used by San Francisco “and would consider expanding ours to include some of that.”

“We’ve had noncitizen voting for a while, but given the national context, it’s taken on renewed importance as an expression of the inclusive values we hold important in our community,” said Kate Stewart, the mayor of Takoma Park. “We want to make sure people who live in our city have a say in local government, and while we felt that way for decades, given the climate we’re all living in, unfortunately we think it’s important to not only talk about being welcoming and inclusive but to show that we are.”

Arguments against noncitizen voting generally center on claims that it weakens the value of citizenship, could discourage immigrants from seeking eventual naturalization, and could increase the likelihood of voter fraud. Indeed, even immigrant-friendly liberal cities have rejected noncitizen voting for these reasons. Portland, Maine, rejected a ballot measure for noncitizen voting in 2010, while Burlington, Vermont, rejected its own in 2015. Legislative efforts have also launched and failed several times in places like Washington, DC, and New York City.

Still, there’s reason to think noncitizen voting could expand, especially as more cities, like Boston, see the move as a way to push back against the anti-immigrant policies the federal government is imposing on them. But it could take time, and several tries: Unlike a campaign to raise the minimum wage to $15 an hour or Medicare for All, noncitizen voting generally takes a long time to explain and build support for—as most people upon first hearing about it assume it’s illegal or un-American. But attitudes change, as the eventual successful effort in San Francisco showed.

Plus, there’s the fact that noncitizen voting is already expanding across the globe, especially in the last few decades. “More than 45 countries on nearly every continent allow resident noncitizens to vote at the local, regional, or national level in the host countries’ elections,” write Hayduk and Coll, citing the European Union, Venezuela, Israel, and New Zealand as examples.

With 22.5 million noncitizens currently living in the United States, advocates remain cautiously hopeful about the future. If all those people could one day vote, the political implications for where they’re concentrated could be tremendous.

“We know federalism is a cornerstone of American democracy, and noncitizen voting is one way that we in San Francisco can set the tone for how we think about engaging immigrant communities to feel a sense of belonging when the federal climate signals to them they are not welcome,” said Pang of Chinese for Affirmative Action. “This has already been a tremendous victory, and whether or not the turnout is huge—that’s not the right metric to measure how effective and positive it is.”