U.S. Immigration and Customs Enforcement investigations have revealed that hundreds of illegal immigrants from the Middle East and countries associated with terrorism have entered the country through Mexico, and according to a study done for the Border Patrol, around 90 percent of the people who try to get in that way eventually make it.
President Clinton built a wall to try and stop it, and President Bush tried to tackle the problem with technology, initiating an ambitious program he called a "virtual fence," that would allow the U.S. to visually monitor most of the border.
The bureaucrats at Homeland Security changed the name of the program to the "Secure Border Initiative Network" or SBInet, and after three years and a billion dollars, 60 Minutes correspondent Steve Kroft decided to see how it was going.
An 80-foot tower near Sasabe, Ariz. is just one of a network of electronic observation posts that dot the landscape along the Mexican border south of Tucson.
They're part of a system that the Department of Homeland Security intended to be the eyes and ears of the U.S. Border Patrol, scanning the Southern frontier for migrants, drug smugglers, and even international terrorists trying to enter the country illegally.
"These towers are located based on geography, terrain, and what the Border Patrol knows about typical traffic patterns. So these are placed because they're where we believe they're gonna be most effective," Mark Borkowski, the executive director of this huge technological undertaking for Homeland Security," told Kroft.
Each one of the observation towers is equipped with long range radar and high resolution cameras, and is connected to underground sensors. It was designed and built by Boeing, one of the nation's largest defense contractors; Borkowski himself is a rocket scientist who used to work for NASA.
"It's not rocket science. But it is still a complex, ambitious project, particularly the way it was originally designed, which was to cover the entire border with this technology," Borkowski told Kroft.
Asked why the United States needs this project, Borkowski said, "Well, we need it because we need to secure our borders. I think it's a national imperative that we want to secure our borders."
In principal it's not that much different from the security systems you might find in someone's home, office building, or the convenience store down the block - only on a much larger and more sophisticated scale.
The cameras and sensors on the towers are capable of picking up the slightest movements up to six or seven miles away, and shooting off an alert to a Border Patrol station, where an agent can then focus the cameras on the exact location. The visual information allows them to discern whether the intrusion is a threat that needs to be investigated or one that can be ignored.
"So in simple terms, what you want to do is you want to be able to look at the entire border with Mexico?" Kroft asked.
"Right. Where it's appropriate to look at the entire border, right," Borkowski replied.
"And then, if you see somebody crossing, you can dispatch Border Patrol people out to catch them?" Kroft asked.
"Correct," he replied. "We have a view of this person. We know if they're by themselves or with other people. We know if they're riding or not riding. We know if they're carrying things or not carrying things."
But unfortunately for Borkowski and the two people who had the job before him, it has proven to be much easier said than done.
When Boeing was awarded the initial contract back in 2006, it made some rather extravagant promises, claiming it could complete the project quickly and that virtually no one would be able to sneak across the border undetected.
Asked how this has worked out, Richard Stana, the director of homeland security issues for the Government Accountability Office, said, "Well, it hasn't worked out so far as well as they had hoped."
And that is putting the best possible face on it. One of Stana's jobs has been to investigate and monitor the project for Congress.
According to Stana, Boeing promised to complete the first 28 miles of the surveillance system in just eight months and wire the entire Mexican border in three years.
"In fact, this was supposed to be all deployed by now, by 2008-2009. The entire Southwest border was to be covered by SBI," Stana said.
But according to him that hasn't happened and that "we're still in the early stages."