Probably three reasons :
Mexican authorities are corrupt, and can be bought cheaply
ISIS is better armed than Mexican Federales.
Mexico wants to export ISIS for idealogical political reasons to control the Southern border and keep it open.
The fact that BOrder Agents have seceed the first thirty miles of the border to Mexico says volumes.
HEY!
When are we going to wake up?? We got real issues that deserve national attention!!
TO HELL with this news about ISIS at our doorstep with an unoccupied door thats wide open.
WE GOT PIZZA JOINTS THAT WON’T CATER TO GAYS!!!