"Reckless"is letting a few in by accident through negligence.
Somehow the term falls far short of what has been done.
A relatively successful program of border control was systematically dismantled, with materials sold for scrap prices, and the borders flung wide open, including flying in illegals from elsewhere.
"Migrants", "refugees", whatever you want to call them, the influx (invasion) was unprecedented in American history, without so much as the checks carried out 100 years ago at Ellis Island, in a day and age where so much more should have been possible.
This isn't recklessness, it isn't carelessness, it goes beyond mere negligence and nonfeasance, and goes into the realm of treason. When the gates were flung open, the invaders didn't even have to build a horse.