McALLEN, Texas (AP) — In Republicans' bid to retake control of Congress, this traditionally Democratic stretch of South Texas has quietly become a top battleground.

After making unexpected gains last November, the GOP is zeroing in on a trio of House seats in the region as key targets heading into next year's midterm elections. They include the 15th Congressional District, which hasn't sent a Republican to Washington since its creation in 1903, but where a GOP newcomer came within three points of winning in 2020.

Republican leaders believe the party is on the precipice of a political realignment among Hispanic voters in communities along the U.S.-Mexico border like McAllen. Inroads among Latinos could potentially offset the party's growing vulnerabilities among voters, particularly in the suburbs. The elections next year will determine whether these shifts are enduring or a more limited response to the turbulent politics of the Trump era, as Democrats hope.

But with Congress having just a six-seat majority in the House, Democrats in Texas say the party has to take the threat seriously.

"I don't think there's any question that we need to be concerned about it and we need to put more resources into it," said Gilberto Hinojosa, the chair of the Texas Democratic Party. 

Republicans' top target in the area is the 15th District. It currently stretches from the border's Hidalgo County, which is more than 90% Hispanic, to the eastern suburbs of San Antonio. Voters here have never sent a Republican to Washington, which is why national party leaders were so stunned when Monica De La Cruz-Hernandez, a small business owner, came within 10,000 votes of beating Rep. Vicente Gonzalez, a two-term Democrat.

Sitting behind her office desk in Alamo earlier this month wearing cowboy boots and a campaign T-shirt, De La Cruz-Hernandez, who is running again, credited her performance to former President Donald Trump. She said his "colorful personality" had sparked new interest in national politics that changed many Texans' minds about politics.

"When they paid attention to what was happening on the national stage, I think that the lights started to turn on for people where they saw, you know what? My conservative values no longer align with the Democrat Party," she said. "The bottom line is that the Hispanic values are pro-God, pro-life and pro-country. And we are conservatives down here."

Border security, she said, is "number one issue from the north side of the district to the south side of the district," as border crossings have soared. And Republicans in the state have been laser-focused on the issue, with Trump staging a post-presidential visit to the border last month that drew hundreds of supporters.

Democratic state lawmakers have been focused on blocking a sweeping election overhaul bill and have been camped out in Washington — though some Democrats representing the Rio Grande Valley did not join them.

Nationally, the Pew Research Center estimates that about 38% of Hispanic voters supported Trump in 2020, compared with 28% in 2016. While Trump lost Hidalgo Country by 17 percentage points in 2020, he more than doubled his support from 2016, when he lost by a whopping 40 points, earning just 28% of the vote. And he flipped a handful of other nearby districts, including Zapata County, which Democrat Hillary Clinton had won 66%-33%, and Kenedy, which Clinton carried 53%-45%

Beyond those gains, Republicans point to other data points to support their optimism. Javier Villalobos in June was elected mayor of McAllen, becoming the first Republican to hold the post in decades. Texas' redistricting process, which is controlled by state Republicans, could produce districts that are even more favorable to GOP candidates as the lines are redrawn to reflect the state's gain of two congressional seats.

Villalobos, who joined Trump at his border briefing and was hailed as a "superstar" by other officials at the event, said he saw his election as part of a trend driven both by Trump as well as economic changes as more Hispanics have entered the middle class.

"Historically, it's been Hispanic people are very conservative, but they vote traditionally Democrat. And little by little, even the older people are changing," he said. "And that's a beautiful thing. Competition is good."

It's unclear whether the gains Republicans made in 2020 will carry over when Trump isn't on the ballot in 2022. Democrats insist their poor performance last year was a one-off and point to unique circumstances, including the party's decision to largely forgo in-person campaigning during the pandemic. The McAllen mayor's race, they also note, was nonpartisan, and turnout was less than 10,000 votes.

Gonzalez, the Democratic incumbent in the 15th District, insists he's unfazed by the strong showing of De La Cruz-Hernandez. He described last year's results as "an anomaly" driven by a pandemic that devastated the district, killing thousands of residents, including some of his personal friends, and dissuaded many elderly voters from casting their ballots.

He pointed to concrete gains made under the Biden administration that he will campaign on, including an economic recovery, mass vaccinations and relief dollars that helped keep small businesses open.

"Everyone at the end of the day is running on results and the work that we've done and we will be running on what we've done for the people," he said.

But Hinojosa, the Texas Democratic chair, was more cautious. He acknowledged the party was caught off guard by a surge in first-time voters who cast ballots for Trump. Because no one thought the races would be competitive, little money and effort were spent on the contests, with no canvassing, phone banking or get-out-the-vote drives.

Trump's message, he said, also resonated with voters, especially in the Rio Grande Valley, where poverty rates are high and the economy remains hobbled by a shuttered southern border. He cited concerns about the future of the oil and gas industry, the border, and calls from some Democrats to "defund the police," which "freaked out" many voters who have ties to law enforcement.

"It was just almost a perfect storm for the Republicans down here," he said, noting the party lacked the "resources that were needed to shore up support down here" because the race's weren't considered competitive.

In preparation for next year's election, he said he has already held meetings across South Texas with local leaders, forming coalitions along the border, as well as hiring a full-time organizer.

"We're going to spend a heck of a lot more money and lot more time than we ever have before just to make sure that what Republicans say is going to happen won't happen," he said. "We're not going to take any chances."

But interviews with voters suggest there is work to be done.

Eryc Palomares, 42, who lives in McAllen and works in a medical laboratory, said he was thrilled to see others like him who had broken their allegiance to the Democratic Party "because that's all we've seen, that's all we've known here."

It's "as if they have you already brainwashed: Go vote Democrat. That's all it was here," said Palomares, who now tends to vote Republican.

"People are waking up," said Manuel Pescador Jr., 54, an occupational safety consultant and local activist who lives in McAllen.

Pescador Jr. said he switched parties seven years ago, rejecting what he saw as a culture of "handouts and false promises," and now rails against immigrants who enter the U.S. illegally.

"They come here, they refuse to assimilate and they're here to use everything they can, in any way they can. And so that's why I call them 'depleters,'" he said. "That's why that Hispanics that can vote, vote Republican, because we know who's coming in."

Joe Guerra, an independent who lives in McAllen, didn't vote in last year's presidential election, but said he wasn't at all surprised by the GOP's gains.

"The Republican Party was, for years, just a token presence here. But the conservative spirit has always been here," he said. "They were always there and (Trump) just had the ability to bring them out. That's who they've always been."