Only 800 troops? Against 10 or 14 thousand illegals?
They kinda ran right over the top of the 500 Mexican federales that were flown to the Guat/Mexican border. That was when the horde was about 2,000 not 12,000.
The excerpt states that that is in addition to the 2000 National Guard that are already there. Add in another 1000 - 2000 Border Patrol and it's a pretty substantial force.
Besides, the crossing point can be completely blocked by rolls of concertina wire in a very short amount of time.