On a recent weekday afternoon, a group of Latino university students near the Southwestern border draped themselves in flags festooned with President Trump’s Make America Great Again slogan, carried pro-Trump signs and set out to recruit new voters — like Victor Ibarra.

“This area is no longer just for Democrats,” Mr. Ibarra, an exuberant 20-year-old political science major, said as he joined their ranks and draped a MAGA flag around his neck. “A lot of people are changing the way they used to vote.”

So much has already happened at the dawn of the second Trump term that could resonate in Texas’ Rio Grande Valley border region: raids and deportations; the opening of a migrant internment camp at the U.S. base in Guantánamo Bay, Cuba; the president’s attempt to end automatic citizenship to babies born on U.S. soil; tariffs threatened, then pulled back, on Mexican goods; and the U.S. military dispatched to the border.

All of that has only underscored a question that might have more political importance than any other in the near future: Does the rightward lurch of Hispanic working-class voters have staying power, or can Democrats win them back?

A new breed of Latino leaders is emerging in this once-solidly Democratic enclave to find the answer.

Alexis Uscanga, 21, who once idolized President Barack Obama, is typical of the Republicans asserting themselves at the University of Texas Rio Grande Valley in the border city of Edinburg, Texas.