Donald J. Trump’s brand of populism has been widely viewed as an appeal to white voters: Republicans around the country continue to exploit the fear that the left is attacking religious values and wants to replace traditional white American culture with nonwhite multiculturalism. But similar grievances have resonated in the Rio Grande Valley in a profound way, driving the Republican Party’s successes in a Democratic stronghold where Hispanics make up more than 90 percent of the population.

The difference is in the type of culture believed to be under assault. Democrats are destroying a Latino culture built around God, family and patriotism, dozens of Hispanic voters and candidates in South Texas said in interviews. The Trump-era anti-immigrant rhetoric of being tough on the border and building the wall has not repelled these voters from the Republican Party or struck them as anti-Hispanic bigotry. Instead, it has drawn them in.

“Our parents came in a certain way — they came in and worked, they became citizens and didn’t ask for anything,” said Ramiro Gonzalez Jr., a 48-year-old rancher from Raymondville, on the northern edge of the Rio Grande Valley. “We were raised hard-core Democrats, but today Democrats want to give everything away.”