Currently, trade coming through Presidio is extremely low. Freight valued at about $18 million went through Presidio’s port of entry in June. Comparatively, $6.6 billion went through El Paso to the northwest and $454 million through Del Rio to the east.

Mexico, for its part, sees promise in the Ojinaga-Presidio border crossing. Nearly 500 miles of the U.S.-Mexico border — more than one-fifth overall — stretch between the border crossings at Del Rio and El Paso, and Presidio is right in the middle of it, city economic development adviser Brad Newton points out. Mexico has made a huge investment in the Ojinaga-Presidio crossing: Mexico President Enrique Peña Nieto visited Ojinaga on Thanksgiving in 2013, and announced he was going to build a model port of entry there.

“Mexico is definitely gearing up to come through here. And so now, we're gearing up to accept their traffic,” Newton said.

But tariffs imposed by the Trump administration on aluminum and steel have caused a new wave of worry. The biggest industrial player in Presidio is a cross-border maquiladora called Solitaire that manufactures mobile homes. (The large supply of inexpensive labor from Mexico — boosted by the North American Free Trade Agreement — spurred the rise of manufacturing plants along the border.) Solitaire uses a significant amount of steel and aluminum, and although it recently doubled its production, tariffs could potentially increase prices to the point where it cuts production, John Ferguson said.

“One thing we’ve been banking on for the past 30 years is to try and grow international commerce with Mexico, and all of a sudden you’ve got some trade tariffs, that could put a damper on that,” John Ferguson said.

Even if the bridge expansion attracts more trade, Presidio almost certainly can’t accommodate it without state or federal assistance. It can barely support its own residents — during the holidays when families flow in, parking is scarce and Presidio’s two small hotels quickly book up — and opening businesses and expanding city infrastructure is a notoriously slow process, says Nunez, the city councilwoman. Her brother tried to construct a large office building in the area for their family company, but the land surveyor, which serves both Presidio and Marfa — a small city about an hour’s drive north — was busy. After a year, the land surveyor still hadn’t completed the required survey.

Presidio County is vast — at almost 4,000 square miles, it's three times the size of Rhode Island — and so sparsely populated that local government resources that affect people’s daily lives are scarce.

There’s no Social Security office. The Department of Motor Vehicles is only open for half a day each week, on Wednesdays. The closest fully functioning county courthouse is in Marfa. Hurd periodically sends staffers to visit Presidio, but his closest permanent presence — a district congressional office in Fort Stockton — is 153 miles away.

Presidio’s public library has become a de facto help desk — a refuge of the cash poor. Carmen Elguezabel, Presidio’s library director, said people visit her for all sorts of problems: to apply for federal government benefits, to take driving tests. Farmers show up, too, to ask for help renewing their special equipment tags.