This is consistent with what I was told by a border patrolman, whom I saw as a patient a couple of weeks ago.
I also understand we have a huge "hole" in the fence, along the "sovereign" Tohono O'odom Reservation, where a nice chunk of the drug/human running occurs, courtesy of the tribal government.
I worked at the Lukevill POE, just west of the Tohono O'odom Reservation.
The Tohono O'odom Council is actively involved in smuggling drugs and illegals. We've caught them in the act.
As with catching the Mexican military in the act, DC steps in and tells us to release them.