Pedestrians trek up the new pedestrian walkway to the Mexico border crossing at San Ysidro, which is part of the $741 million expansion effort. Life at the border in San Diego is different than the picture painted by presidential candidate Donald Trump. (Lenny Ignelzi/AP)

Thirty years ago, when Jerry Sanders was a captain in the San Diego Police Department, a long stretch of the nation’s southern border was marked by a waist-high cord. International pickup soccer games ended at dusk when the Mexicans ducked back under and went home.

Sanders carried this image with him as the city’s police chief and then as mayor. Now head of the region’s Chamber of Commerce, Sanders is disturbed by the national discussion about the border, especially GOP front-runner Donald Trump’s insistence on labeling Mexican migrants as drug dealers and rapists.

“There’s no boogeyman on the south side of the border. We know that,” said Sanders, 65. “There’s our families on the south side.”

While Trump and other GOP presidential candidates push for a giant wall between the United States and Mexico, San Diego is literally building a bridge. In December, an international group of developers, which includes real estate magnate Sam Zell, plans to open a pedestrian walkway that bypasses the regular U.S. border crossings and directly connects San Diego to Tijuana’s international airport.

Meanwhile, all five members of San Diego’s congressional delegation, including stalwart Republican Reps. Darrell Issa and Duncan Hunter, have successfully advocated for the $500 million in additional funds needed to expand the main border crossing. And the city’s new mayor, Kevin Faulconer (R), traveled to Tijuana during his first week in office in 2014 and has called for comprehensive immigration reform.

“It’s beyond politics,” Faulconer said. “It’s about where we are in the world.”

Where San Diego is, geographically and philosophically, may best be explained by one number: 59 million. That’s how many people traveled back and forth last year at the main checkpoint, making the city home to the busiest — and most congested — border crossing in the Western Hemisphere.

The logjams are so bad at times that it can take hours to cross the border. The city’s English- and Spanish-language radio stations broadcast border wait-times alongside the local weather report.

As a result, many people decide not to bother with the hassle of crossing, according to a widely cited study by the regional association of governments, and local businesses balk at expanding their manufacturing to Mexico because of the difficulty in trucking finished products back to the United States.

All told, the study found, cross-border commerce brings $6 billion a year into the region, but congestion at the border steals another $7 billion and costs the region as many as 62,000 jobs.

“When you remove the social debate and it’s just an economic debate, it’s hard to argue against that,” Sanders said.

To help the flow of traffic, the federal government in 2009 began expanding the region’s main border crossing, an effort that would add dozens of automobile and pedestrian lanes while making it more efficient for Homeland Security agents to check people coming into the country. The problem was that the $741 million project was funded in three phases and the last two chunks totaling a half-billion dollars weren’t in the federal budget.

By late 2013, one of the remaining phases had the support of President Obama and the Senate, but not the GOP-controlled House. San Diego’s House Democrats turned to their Republican counterpart, Issa, for help.

“Darrell was the guy who took the message to the Republican side,” said Rep. Scott Peters, a Democratic member of the San Diego delegation.

The funding also won the support of Hunter, San Diego’s most prominent immigration hawk. It made the final version of the budget and got the president’s signature in January last year. Money for the final phase was approved shortly after that. Construction on the border crossing is scheduled to be completed by fall 2019.

Hunter didn’t respond to a request for comment. But Issa said his support for the effort had nothing to do with immigration and everything to do with the region’s economy.

“All politics is local,” Issa said.

But not all locals, including the politicians united behind the border project, are on the same page when it comes to broader immigration and border issues. Peters and his two Democratic colleagues supported the large-scale immigration reform bill passed by the Senate two years ago. Issa has introduced a number of smaller-scale bills, including those that would provide more visas for tech and other skilled workers. Hunter was behind the effort to withhold money from “sanctuary cities” after an undocumented immigrant killed a woman in San Francisco in June.

Indeed, lumping any issue that deals with the border and immigration together troubles Peter Nunez, a former U.S. attorney in San Diego and board chairman of the D.C.-based Center for Immigration Studies, which advocates for more restrictive immigration laws. Nunez said he has no problem with improving the region’s border crossings, but thinks local politicians’ efforts to boost business can come at the expense of preventing drug trafficking, illegal immigration, smuggling and terrorism.

U.S. and Mexican federal agents recently discovered a long, underground drug tunnel with ventilation, rail and lighting systems, connecting warehouses in Tijuana and San Diego. The agents seized more than 12 tons of marijuana as part of the raid. It was the 10th such tunnel found in the San Diego area since 2006.

“I’ve always worried that the Chamber of Commerce approach would dissolve or decrease our ability to protect the American public,” Nunez said.

Still, San Diego’s immigration discussion is different now than those in the past.

Two decades ago, David Alvarez walked out of his San Diego middle-school classroom alongside many other Mexican-American students across California to protest Proposition 187, a ballot measure that would have stripped state health care and public education from undocumented immigrants. After a nasty campaign, the measure passed, but it was quickly overturned in court.

Proposition 187’s most prominent supporter was then-Gov. Pete Wilson, a Republican who had previously been San Diego’s mayor. Alvarez, now a San Diego Democratic city councilman who represents border neighborhoods, said Wilson’s backing of the measure led to the erosion of GOP support in California, a view shared by many in the state.

“We know who was out to get us,” he said.

In San Diego, Alvarez said, Republicans have changed. Although he is frequently critical of Sanders’s mayoral tenure and unsuccessfully ran against Faulconer for mayor, Alvarez agrees with their stances on the border. “We have a common goal,” he said.

There may be no better manifestation of that goal than the pedestrian bridge funded in part by Sam Zell.

Zell, who declined to comment, and a group of Mexican and American developers began construction last year on the $120 million bridge that will connect San Diego with Tijuana’s airport. Flights in and out of Tijuana are cheap. The idea is that the bridge would attract travelers willing to pay about $15 to park, go through customs on the U.S. side, and then walk to the airport. The trip, just 390 feet, will be shorter than an average city block. The project is scheduled to open by the end of the year. From the parking lot, you can already see the bridge rising over the barbed wire fences along the border.

Dillon is a reporter and editor at Voice of San Diego.