But teams of lobbyists, including former Senator Alfonse M. D’Amato, a New York Republican, and Benjamin Abrams, a former top aide to Representative Steny H. Hoyer, a Maryland Democrat and House minority whip, have already been pressing Homeland Security officials and lawmakers on behalf of their clients, efforts that have been backed up with millions of dollars of industry campaign contributions.

Homeland Security would have to decide, in consultation with Congress, how to divide the money — on long-range cameras, radar systems, mobile surveillance equipment, aircraft or lower-tech solutions like more border agents or physical fences — decisions that would determine how various contractors might fare.

“It has been a tough time for the industry: people have been laid off or furloughed,” said James P. Creaghan, a lobbyist who represents a small Texas company, Personal Defense, which is trying to sell more night-vision goggles to Homeland Security. “This could help out.”

Northrop has won some important allies on Capitol Hill, including Senator Thomas R. Carper, Democrat of Delaware, the chairman of the Homeland Security and Governmental Affairs Committee, who is urging the department to invest more in Northrop’s drone-mounted surveillance system, called Vader. General Atomics, which Mr. D’Amato represents, has so much support in Congress that it has pressed Homeland Security in recent years to buy more Predator drones than the department has the personnel to operate, so they often sit unused, according to an agency audit.

The specific requirement in the legislation now before the Senate is that Homeland Security must install surveillance equipment or other measures that would allow it to apprehend or turn back 9 out of 10 people trying to illegally enter across all sectors of the southern land border. The department would be prohibited from moving ahead with the “pathway to citizenship” for immigrants already in the United States until this new security strategy is “substantially operational.”

The bill is scheduled to be taken up for debate on the Senate floor next week, and certain Republicans have already drafted amendments that would make the requirement even more demanding, explicitly mandating that the 90 percent standard be achieved before the pathway to citizenship can proceed.