“We have to be honest,” María Teresa Kumar, the president and co-founder of Voto Latino, a nonpartisan organization, told me last fall. “When it comes to voter registration, each party is looking to the Latino community and the African-American community for enough votes. They don’t need us all.” From her office in Washington, she directs efforts to engage young Latinos who are often navigating the political system for their families. “Our job,” Kumar said, “is to do true political empowerment: It’s mass mobilization and mass participation. And for parties, it’s about how little do they need to spend to get over the top.”

If Virginia’s battleground status suggests a triumph of the Latino vote, it also provides a cautionary tale about its limitations. In early August, Senator Tim Kaine, Hillary Clinton’s running mate, appeared in the green-and-yellow gymnasium of Huguenot High School in Richmond. “Yes, we Kaine!” the crowd shouted under the floodlights. His homecoming rally doubled as a history lesson. Kaine pointed out that Virginia had gone 170 years without a president or vice-president. When he moved to Virginia in 1984, he said, neither Republicans nor Democrats bothered to campaign in the state, a situation that he attributed to a conservative lock on power that depended upon marginalizing women and minorities. “We pushed you away from the table,” he said. But since Barack Obama turned Virginia into a battleground, it has become a campaign stop for every would-be president. “It’s much better to live in state where no one can take you for granted,” Kaine said.

The shift that brought volunteers like Keisy Chavez to the Democratic table actually began long before Obama. When Mark Warner was elected governor in 2001, his campaign strategy relied on winning rural, Nascar-loving Republicans, not on including minorities. But Kaine’s own gubernatorial victory in 2005 used an urban-suburban strategy that relied upon the participation of Northern Virginia’s fast-growing, multiethnic communities. Given Kaine’s experiences arguing civil rights cases and his work as a missionary in Honduras, the shift may have reflected personal affinities. It was also a canny response to Virginia’s changing demographics. According to the University of Virginia’s Demographics Research Group, in 1970 only one in 100 Virginians were born outside of the United States. By 2012, that ratio had increased to one in nine. Such demographic transformations are hardly unique to the state. Between 1990 and 2008, the number of Latinos living in Arkansas, Alabama, Georgia, North Carolina, South Carolina and Tennessee grew by 602 percent, prompting political scientists to dub the region the “Nuevo South.” “If you put your faith in the Virginia voter,” Kaine recalled telling the candidate Obama in 2008, “You’re going to win Virginia.”

Yet the majority of Virginia’s General Assembly is still Republican, and only two of its state-level representatives, the delegates Alfonso Lopez and Jason Miyares, are Latino. Harry Wiggins, the chairman of Prince William County’s Democratic Committee, described the problem like this: “We win the presidential. We won for Mark Warner. We won for Tim Kaine. We won for Terry McAuliffe. Yet the county board we lose, because they have off-year elections, and we have very light turnout.”

Figueroa is already preparing for the inevitable drop. “The numbers are going to plummet next year in places that count, like Prince William,” he told me. In 2015, the Census Bureau weighed Prince William County at 22.3 percent Latino, 21.8 percent African-American and 8.7 percent Asian. The chairman of its board of supervisors, however, is Corey Stewart, a Republican, who is also chairman of Donald Trump’s campaign in the state. “When he is president and I am governor, you’re going to see one helluva tag team in Virginia, and we’re finally going to remove illegal immigrants,” Stewart told The Richmond Times-Dispatch in June. The gubernatorial race will occur next year, when no other state in the country except New Jersey will be holding elections.

While Kaine spoke, Figueroa stood near the press box, tapping at his phone and taking in the scene. In the days leading up to the rally, he mentioned several times that he was working to make the event “blacker and browner.” His handiwork was evident in the V.I.P. bleachers directly in front of the television cameras, where a group of people sat, many of them wearing the unmistakable bright blue-and-white jerseys of El Salvador’s national soccer team. They were students, parents and teachers associated with the English-as-a-second-language program at Huguenot High School and its International Club. Their V.I.P. seating had come from Figueroa. Their homemade red, white and blue sign “Juntos Se Puede!” (“Together we can!”) gave Kaine a camera-ready opportunity that he seized, pointing to them and leading a round of “Sí se puede!” — a chant that will always have special resonance for those who know that it originated not in 2008 with Obama but with Cesar Chavez and Dolores Huerta in 1972.

After Kaine finished his speech, as “Shake It Off” blasted through the gym, several of these students joined the throng vying for an opportunity to snap a selfie with him. I asked two of them what they knew about Kaine. “He was mayor of Virginia,” one said. The other added that he had lived in Honduras and was a friend of Latinos. That was all that they seemed to know. Two parents I spoke with told me, in Spanish, that they understood only pieces of Kaine’s speech, which was in English. This explained why one father appeared so poker-faced through much of the rally. Unless his son translated the speeches for him, he couldn’t form an opinion. He didn’t understand what was being said.