A tantalizing but pertinent question!
Ans: Perhaps because long ago we formed a government that swore to protect the various states from foreign invasion. We now each take money out of our pockets and pay for that very purpose and even regularly vote for a representative who swore the money would be well spent and the job well done.
Presently, our borders are unenforced, our government provides a cell phone and air transport to illegal entrants, and we taxpayers are burdened, one way or the other, with providing those entrants a comfortable presence.
It is obvious someone screwed up, was it us?
Of course it was “us”. Patriots went along with government overreach time after time, and it was all a test, how far could they go. Just a few examples:
Abortion laws began with “abortions will only be used in extremely rare circumstances”. It has now morphed into abortion on demand, late term abortion and even advocating allowing newborns who survive abortion to die.
Cigarettes were banned on governmental property, which was fine. Then it became dangerous when smoking in PRIVATELY owned restaurants and bars became illegal.
The border? There have been so many transitions to where we are today that it would take a week to outline.
Gay rights went from “we just don’t want to be discriminated against, including hate crimes( which is reasonable). Now we have gay marriage, adoption, and now demanding early childhood indoctrination of children, even surgical and hormone intervention of kids.
THEY NEVER STOP.
I’ve tried to think of what citizens could do - i think a large group of retired military could just use gernades to blow up the ground along the border - set off enough of them to discourage people from crossing as they’d never know where these wil go off.