Then Nafta was signed in 1993, and the number of commercial trucks went from one a week to as many as 300 a day. Mr. Vale takes in around $4 million a year in tolls. (Mr. Sparks, 63, would not specify his revenue, but it is also in the millions.)

Mr. Vale has also pursued an array of ventures beyond the bridge. A column of eighteen-wheelers that were waiting to cross belongs to him, and so does the sand in them. He brought the dolomite limestone from a mine in Mexico, and it will travel to concrete producers and asphalt plants across South Texas, earning Mr. Vale millions each year.

He owns about 60 acres around the bridge, and a railroad that runs through the property and links to a Union Pacific line. He is paid to transport pipes, lumber and sheet metal on rail cars that come in from a town a few miles away, but still on the American side.

That mix of ventures has allowed Mr. Vale to indulge in some other pursuits. He drives a cherry red Mercedes-Benz drop-top with a license plate that reads “Cizzle.” He has nine black German shepherds — some of which were flown from Prague for breeding — that live in climate-controlled doghouses scattered across his properties.

“Central air and heat, insulated cedar-wood homes,” he said. “Everybody has them in Texas.”

Mr. Vale does not love leaving Texas, but he has made six trips to Washington since the election to make his case to lawmakers. His pitch is simple: “Don’t hurt the country, don’t hurt the businesses that support you, Mr. President. Don’t hurt the people who are critical to the economic survival of the United States.”