Sadly, at this point bolstering what forces we do have with mobile automated turrets would not be enough. We honestly need to station the military on the border and start shooting at the invaders to scare them off. Those that don't turn around, well, that is what needs to be done. Eventually fewer will come once the price to be paid gets known.
A true tragedy that could have been avoided. The border has not been secured for my entire lifetime. The situation has gone from bad when I was born in late 1979 to outright out of control today.