How ISIS would get into the U.S.

“The physical border between the U.S. and Mexico is far worse than it was before 9/11,” Kephart says. “The refusal by this administration to put modern technology to consistent, strategic use across the border with a clear policy to enforce the law at and inside the U.S. has made for an incredibly lawless situation which our border forces cannot handle, even if they had the go-ahead to do so.”

If al-Qaeda or the Islamic State wanted to enter the U.S., Kephart says, they would likely do it on land — such as at the southwest border — where the infiltrators could arrive anonymously and unofficially. If al-Qaeda or the Islamic State attempted to access the U.S via a port of entry or via the Visa Waiver Program, then they would face greater scrutiny and may place themselves at greater risk of getting caught.

“The most sophisticated terror organizations are financed to be able to send travelers in-and-out, to test our systems, and to see what they can get away with and they do it,” says Jessica Vaughan director of policy studies at the Center for Immigration Studies. “They have a better idea of how it works than many law-enforcement officers do.”