Conversations with voters and activists in Hidalgo County suggested that there is not one answer but many: Women who staunchly oppose abortion voted for the first time; wives of Border Patrol agents felt convinced the Trump administration was firmly on their side; mothers picked up on the enthusiasm for Republicans from friends they knew through church or their children’s school.
For many voters in the region, there is a profound sense of cynicism — a feeling that things will not change no matter who is charge. The border, after all, has been the site of a humanitarian crisis under both Democrats and Republicans. Nearly everyone here knows both undocumented immigrants and Border Patrol agents, occasionally even within the same family. And for many here, law enforcement remains one of the easiest paths to the middle class, and Republicans have portrayed national Democrats as hostile toward the police.
Both Republicans and Democrats are likely this year to start funneling far more money into the region, where enthusiasm for the G.O.P. in 2020 was not limited to Mr. Trump. For the first time in recent history, a Republican came close to defeating the Democratic incumbent in Texas’ 15th Congressional District, which includes most of Hidalgo County and runs north of McAllen up to San Antonio.
In next year’s race for the seat, the Republican candidate, Monica De La Cruz-Hernandez, is again challenging Representative Vicente Gonzalez, a Democrat — but they may be competing on different political terrain if the district’s “bacon strip” shape is altered in redistricting later this year.
At the local Lincoln Reagan Republican dinner in March, Mr. Abbott rallied support for Ms. De La Cruz-Hernandez and encouraged other women like her to come into the G.O.P. fold, speaking in glowing terms about their political potential and saying he had “never been as impressed” with the leadership of a county party.
“I’ve never been onstage with so many accomplished, articulate Latinas as I have been tonight with this group of ladies,” he told an enthusiastic crowd. “This is amazing. If I were the Democrats, I would be very afraid right now, because there is a storm coming, a storm that is going to win Hidalgo County. I wanted to be here in person, wanted to say thank you.”