“could”???
They’ve been here for years, getting ready and waiting for their “GO” orders.
The 9/11 terrorists got into our country through normal channels. Some of them took flight training, how to fly a commercial jetliner. No one in federal law enforcement noticed them.
Now we have an open border allowing anyone to walk on in.
They have no clue on who these people are, where they end up and what they are doing.