The tears begin flowing the moment the U.S. Border Patrol agents swing open the doors of the border enforcement zone, allowing Mexican families to step through and reunite with loved ones at the border fence near San Diego.
The weekly encounters at Friendship Park, across the border from Tijuana, showcase the soft-hearted side of the force protecting America's Southwest border. But during one recent visit some youngsters didn't seem to be buying it.
In March, the National Border Patrol Council, the union that represents agents, had endorsed Donald Trump for president. One teenage boy, a high school student from Oakland, asked a pair of agents why.
"He asked how can Border Patrol agents be supporting hateful rhetoric that seems to contradict the spirit of the … event," said Pedro Rios, director of the American Friends Service Committee, who led the field trip of youngsters to the border and witnessed the exchange.
It's a line of questioning that agents are hearing more often these days. And though the agents that April day didn't respond to the youngster's query, the rank-and-file seem as polarized about Trump as the rest of the nation, with some going so far as to challenge their union leaders' decision.
The union leadership, in a strongly worded endorsement letter that mimics Trump's brash stylings, commended Trump for not backing down from statements considered racist by many. Trump has referred to Mexican immigrants as rapists and criminals.
"Mr. Trump is correct when he says immigration wouldn't be at the forefront of this presidential campaign if months ago he hadn't made some bold and necessary statements. And when the withering media storm ensued he did not back down one iota," read the endorsement letter from the union, which represents 16,500 agents.
Criticism of the endorsement, the first time the union has taken sides in a presidential campaign, has come from all directions. Many agents lean conservative and were Ted Cruz supporters.
Others take issue with backing a campaign built in part by disparaging Mexican immigrants. That's not surprising given the fact that about half of the nation's 18,000 agents on the Southwest border are Latino. And there's no shortage of white agents who hear the Trump backlash from their Latina wives.
"The Border Patrol has changed tremendously in the last 10 to 20 years. It has more than doubled in size and has brought in a lot of new recruits from all over country. That has increased the diversity of the agency," said David Shirk, an associate professor of political science at the University of San Diego.
"While all of them are committed to the agency's mission and believe strongly in work that they're doing, they don't reflect some of the more traditional stereotypes of the Border Patrol as a bunch of white guys chasing Mexicans."
The agency has long cultivated a tough but humane image, befitting its role securing a frontier between two friendly nations. Agents break up human smuggling rings, interdict drugs and apprehend hundreds of thousands of migrants annually.
The agency also has specially trained units that rescue hundreds of lost and dehydrated migrants annually, and coordinates with migrant rights groups in identifying dead bodies and facilitating reunions at the border fence, like the ones held weekly in San Diego.
The efforts earn praise from some community and migrant rights groups, even those who criticize the agency's controversial use-of-force guidelines, which have led to several fatal shootings of unarmed suspects in recent years.
To some, the Trump endorsement could cast doubt over agents, raising questions about whether their actions are motivated more by personal animus against migrants than their professional duty to carry out the law.
Don McDermott, a former supervisor of an anti-smuggling unit in San Diego, said the endorsement vote by a small group of union leaders — 11 in all — threatened to reflect negatively on all agents.
"It is probable that the endorsement of Mr. Trump would expose both the union and the individual members to accusations of xenophobia and even racism," McDermott said. "The reputation of the agency and of every agent is called into question."
Some think the threats of image damage are overblown. In the deserts and mountains, after long treks and mistreatment by smugglers, the sight of an agent is often a relief, they say.
"When you talk to people, migrants say they want to call for help from us. They tell me, 'I don't fear Border Patrol; I fear the cartels,''' said one veteran Latino agent from Arizona who requested anonymity because agents are not authorized to speak with the media.
Union leaders said the leadership backed Trump because he's the only candidate who makes border security a priority. Trump's border wall proposal, along with mass deportations and other security measures, are necessary to reduce illegal immigration, they say.
Shawn Moran, the union's vice president, dismissed concerns that siding with Trump tarnishes the agency's reputation. "I think Border Patrol agents will be tough on enforcement but very generous in terms of empathy and how they take care of those that are in their custody," he said.
But in communities where relations with the Border Patrol have been fraught with mistrust, leaders and agents fear the overheated rhetoric could manifest in ugly ways.
A group of agents in El Paso asked that their local union disavow the endorsement, drawing support from numerous business and community leaders. Their attempt narrowly failed in a 14-13 vote.
"One of the reasons that El Paso is the safest city in the United States is because of the trust developed between law enforcement and the El Paso community," read a statement signed by several law enforcement and city officials from the area. "This trust is undermined by the [union] endorsement of a candidate for president who demeans and degrades immigrants and who has lied about the threats that exist at the U.S.-Mexico border to advance his bid for president."