Mexican nationals deported from the U.S. protest by graffitiing over an image of likely Republican presidential candidate Donald Trump on a section of the border fence between Mexico and the United States, on the outskirts of Tijuana, Mexico, May 10, 2016. (Stringer/Reuters)

To save time, Adriana Zavala would take a shortcut down an empty lane on the way to school, until the afternoon last September when the tattooed Salvadoran gangsters blocked her way.

The threats she began receiving that day — sell our drugs to your classmates or we’ll rape you — propelled the teenager, her father and 13-year-old sister to begin a five-month odyssey from El Salvador that has ended, for now, in this Texas town. They are among thousands of migrants arriving at the U.S. border in what authorities fear could be another surge of Central American families.

“In my country, they’re going to kill me. And I can’t die right now. There are so many things I want to do,” said Zavala, a 17-year-old who wants to be a chef and take singing classes.

On the U.S. campaign trail, illegal immigration is a hot-button topic, with the presumptive Republican presidential nominee, Donald Trump, vowing to build a 1,000-mile border wall. But along this stretch of Texas border, where migrants climb over and walk around existing fencing, such proposed solutions tend to draw scorn, even from Trump fans. And the politician’s tough talk, people here say, might actually be attracting more migrants.

Children play at the Sacred Heart Catholic Church shelter in McAllen, Tex. (Josh Partlow/The Washington Post)

Although the overall number of migrants apprehended along the border this year has not yet reached the proportions of the 2014 flood of Central Americans, some believe that could happen, with a summer surge before the presidential election in November.

“We’re definitely on track to catch up to it, which is not a good thing,” said Chris Cabrera, a Border Patrol agent and union representative here. “The political climate has a lot to do with it.”

The upcoming presidential election marks a fork in the road for U.S. immigration policy: A Democratic victory could lead to more unauthorized immigrants getting permits to work and live in the United States. Trump has vowed to build the giant border wall, deport millions of undocumented immigrants and block remittances. Intense violence and a lack of job opportunities are the driving forces behind the Central American migration, and critics say those problems will continue to push people northward regardless of whether there is a bigger wall. For some of the migrants, sooner seems more appealing than later.

Trump “says he wants to build a wall. They want to get over before he builds it,” said Mario Saucedo Mendoza, who works at the Senda de Vida migrant shelter in Reynosa, the Mexican city across the border from McAllen. “He’s said these things, and people are trying to get in front of him, they are trying to cross now.”

Mexicans have historically made up the largest nationality apprehended by the Border Patrol: There were 187,284 detained last year. The immigration from three Central American countries known as the “Northern Triangle” — El Salvador, Honduras and Guatemala — reached its high-water mark in 2014, when 227,371 people were apprehended by U.S. authorities. That number dropped sharply to 160,496 last year, but the decline is somewhat misleading, because Mexican authorities, under U.S. pressure, began detaining far more Central Americans en route to the United States. Taken together, U.S. and Mexican authorities detained 332,430 Central Americans last year, nearly as many as the 347,085 people captured in 2014, according to government statistics.

This spring, the numbers appear to be rising again. The figures on Central Americans detained in Mexico are above 2014 levels. The Sacred Heart Catholic Church shelter in McAllen, which opened in June 2014 amid the surge and has since taken in more than 35,000 people, has seen days this month with more than 200 migrant arrivals, something that has never previously happened. Sister Norma Pimentel, executive director of Catholic Charities of the Rio Grande Valley, said that the Border Patrol sends migrants when it has run out of space in centers where the detainees are held before proceeding to immigration court.

McAllen, Tex.

“This is overflow,” she said, as Central American children played with donated toys and their parents chose from piles of secondhand clothes, arranged by gender and size. “This year, specifically this month and this couple of weeks, our numbers have increased a lot.

“The families are arriving because it’s impossible to live in their home countries,” she added. “They know their child runs a high risk of being killed, of being kidnapped, of being taken away, and they’ve seen this happen to other people, so they figure out: We have to go.”

Yenis Constancia Viuda de Cruz, a 26-year-old mother of three whose husband was slain by Salvadoran gang members in 2010, decided to flee out of fear that gangs were trying to recruit her eldest son, 9-year-old Pablo José. With a plan to reunite with her mother, who lives in Silver Spring, Md., Viuda de Cruz paid $2,800 in fees to smugglers and bribes to Mexican officials to reach the United States, she said. Like other migrants apprehended by the Border Patrol, she was made to wear a black ankle bracelet with a blinking light, so authorities could track her movements before an immigration court date in Maryland, during which she would plead for asylum.

“My children were in danger,” she said before leaving on a bus for Maryland. “People say, ‘Why don’t you go to another country?’ There isn’t another country where you can provide something better for your children, where you won’t get harmed. The only one is the United States.”

One factor causing the 2014 Central American migrant surge was a rumor that President Obama was offering amnesty to women and children. The U.S. government has tried to dispel that notion, paying for a barrage of television and radio advertisements in Central America trying to discourage people from migrating. U.S. authorities worked to break up migrant smuggler rings and pressured Mexican and Central American governments to impede the flow of migrants.

On the U.S. side of the border, there are plenty of Trump fans, but even some supporters are skeptical about his idea of walling off Mexico. Border fences and barriers, including sections of roughly 20-foot-tall steel rods, already exist piecemeal along about a third of the 2,000-mile border. Migrants have used ladders and ropes to climb over them, jackhammers to tunnel underneath, blowtorches to cut through them — or have simply trekked around them. The barriers, which don’t always track exactly with the U.S. border, also have divided people’s ranches, Native American reservations and universities, while disrupting the flow of wildlife and commerce.

Ruben Villarreal, a Republican candidate for Congress, former mayor of Rio Grande City and Trump supporter, called the wall idea a “12th-century technical solution to a 21st-century problem.”

“There’s no such thing as a fence that’s impenetrable,” he said. And all the talk of it is “causing a draw” of people.

The migrant attitude is “hurry, hurry, hurry, get there,” he said. The campaign trail talk “is going to encourage people from here to November.”