Two nearly identical text boxes appear on the respective campaign websites for Henry Cuellar and Jessica Cisneros, the Democrats locked in a heated primary runoff to represent south Texas in Congress.

Cuellar’s text box warns voters that Cisneros “would defund the police and border patrol”, which “would make us less safe and wreck our local economy”. Cisneros, in turn, blasts Cuellar for opposing “women’s right to choose” amid a nationwide crackdown on reproductive care.

The parallel advisories read like shorthand for the battle that’s brewing among Democrats in Texas, where centrist incumbents like Cuellar are facing a mushrooming cohort of young and progressive voters frustrated by the status quo.

“I want people to take away from what we’re doing … people-power – people – can go toe-to-toe with any kind of corporate special interest,” Cisneros told the Guardian. “And that we still have power over what we want our future and our narrative to be here in Texas, despite all odds.”

Texas-28 is a heavily gerrymandered, predominantly Latino congressional district that rides the US-Mexico border, including the city of Laredo, before sprawling across south-central Texas to reach into San Antonio. During the primary election in March, voters there were so split that barely a thousand votes divided Cuellar from Cisneros, while neither candidate received the majority they needed to win.

Now, the runoff on 24 May has come to represent not only a race for the coveted congressional seat, but also a referendum on the future of Democratic politics in Texas and nationally.

The House speaker, Nancy Pelosi, House majority whip, James E Clyburn, and House majority leader, Steny Hoyer, have thrown the full-throated support of the Democratic establishment behind Cuellar, while endorsements from progressive icons such as Bernie Sanders, Elizabeth Warren and Alexandria Ocasio-Cortez have elevated Cisneros as a rising star on the national stage.

“If Cuellar wins, this is a story of how the Democratic machine and the old system is still strong in the district. And if Jessica Cisneros wins, the narrative is this is another successful Latina politician … carrying the community forward,” said Katsuo Nishikawa Chávez, an associate professor of political science at Trinity University.

Cuellar did not grant the Guardian’s request for an interview.

Cuellar and Cisneros – both Mexican American lawyers from Laredo – represent two radically different visions of what south Texas is and could be.

Cuellar has served nine terms in the US House of Representatives, where last summer he teamed up with the Republican senator Lindsey Graham to portray migrants as disease carriers and demand that the Biden administration “end the surge” at the US-Mexico border. By contrast, Cisneros, 28, has spent much of her early career fighting on the frontlines for immigrant families and asylum seekers, and part of her platform is more humane border and immigration policies that include a pathway to citizenship for unauthorized residents.

Their strategies also diverge on campaign finance. Cuellar has funded years of congressional bids with contributions from donors that have notably included the National Rifle Association and oil and gas industry Pacs. Cisneros, meanwhile, has publicly sworn off campaign donations from corporate Pacs and lobbyists – and yet still far outpaced Cuellar’s fundraising numbers during the first quarter of 2022.

At least part of Cisneros’s fundraising success earlier this year may be linked to the FBI’s raid on Cuellar’s home in January, which immediately embroiled his office in scandal. A Texas Tribune analysis found that in the days after the raid, Cisneros’s campaign contributions soared, although what exactly the FBI was investigating remains unclear and Cuellar maintains he has done nothing wrong.

Now, in the days leading up to the runoff, another major controversy has taken center stage: the candidates’ opposing views on reproductive care. After a leaked draft opinion went viral suggesting the supreme court’s intention to overturn Roe v Wade – the landmark decision that established a constitutional right to abortion in the US – Cuellar has faced renewed scrutiny from reproductive rights champions as the lone Democratic representative to vote against codifying the right to an abortion last September.

Cisneros, in turn, has vowed to protect that right. In a statement following the draft leak, she called on the Democratic leadership “to withdraw their support of Henry Cuellar who is the last anti-choice Democrat in the House”.

The 2022 election is Cisneros’s second bid to unseat Cuellar, whom she also ran against in 2020 as a first-time, 26-year-old challenger. After she lost that race by less than 4% of the vote, she said she felt compelled to try one more time.

“What folks were telling us over and over and over again was that, you know, the way things are right now isn’t working, and that they want a different version – an alternative version – of what south Texas can look like, because they felt like they were being taken for granted,” Cisneros said.

Residents in Texas-28 have a lot working against them, which may explain why some could feel like they and their votes are undervalued. For one, increased voter restrictions, closed or relocated polling places, and other serious barriers that require more time and energy make it so that by design, many Texans of color don’t vote when they perceive an election to be low stakes.

“Everything we see looks to be orchestrated in a way that makes voting for Latinos hard and almost impossible,” said Nishikawa Chávez, who suggested it was hard to look at the Texas government’s actions and not recognize a systemic interest in suppressing the Latino vote.

In a self-fulfilling prophecy, candidates from both parties also chronically underinvest their limited resources in Latino communities like Texas-28 because they don’t know how to reach them and assume they probably won’t go to the polls, Nishikawa Chávez said.

Jen Ramos, a state Democratic executive committeewoman for the Texas Democratic party, has been getting out the vote for Cisneros in Laredo and San Antonio, where some residents have told her it’s the first time their doors have ever been knocked by a political campaign.

“The fact that these folks have never had their door knocked on, have never been contacted before, and we’re talking to people and meeting them where they’re at, that’s a real disappointment for an elected official who’s been in office for as long as he [Cuellar] has,” Ramos said.

If there was anything Ramos noticed growing up in Texas-28, it was the defeated feeling that nothing ever changed within her community, no matter who was in power. “Henry Cuellar has been in office almost as long as I’ve been alive, and yet nothing has inspired any change or difference, nor has he ever bothered to talk to anybody in the community,” she said.

She’s optimistic that things could finally be different with Cisneros representing the district: “I think that Jessica’s race is the very first time in a long time that the region and the community has seen the sense of hope.”

But not everyone in the district agrees with the kind of change Cisneros represents. Texas-28 is a perfect microcosm of how Latino voters are in no way a monolith, and closer to the border’s Rio Grande, constituents trend more conservative, Catholic and pro-gun rights than in San Antonio’s working-class neighborhoods, Nishikawa Chávez explained.

“It’s a huge district, and it’s cut in such a way to maximize Republican votes,” he said. “And so you get a kind of a schizophrenic area.”

Generational and gendered divides complicate matters further. Older voters speak Cuellar’s language around good jobs, border security and Catholic values, while a growing constituency of highly educated young Latinos hear their values represented in Cisneros. Meanwhile, Latina matriarchs are pushing their communities to vote for issues beyond the economy, such as healthcare access, the environment and quality education.

Ultimately, the runoff will come down to who actually turns out, a question that may have a larger impact on how politicians appeal to Latinos in future, Nishikawa Chávez suggested.

“How this election goes is going to tell us a little bit about the future, about how to approach or how to campaign and to get the votes of … Latino voters in the US,” he said.

For now, Cisneros is hoping to find common ground with her neighbors across the district by listening to what they want addressed. “When we’re talking about increasing the minimum wage and Medicare for All,” she said, “they’re kitchen-table issues that, you know, people are much more concerned about.

“Change doesn’t happen overnight,” Cisneros added. “Every little thing that we’re doing every single day, I mean, is helping us build a brighter future. But I do know that when we win on 24 May, I really hope that it is the beginning of change in south Texas.”