Construction? How about our military lays two parallel barriers: 2,000 miles of triple strand concertina wire, 200 yards apart? [At one man-hour per 10 yards, it would take 1,000 men 44 days to lay the first barrier and another 44 days for the second, parallel barrier. The times are cut in half with 2,000 men working.] Monitor for tunneling, collapse the tunnels, and arrest the tunnelers. Make sure no one messes with the wire, and don't give illegals a free ride for being on our territory until they manage to cross both wire barriers on their own. When they do get across, put them in tent cities supervised by MPs and Shore Patrol until their deportation hearings.
They are trying to overwhelm us; let's make sure the challenge and the negligible chance of release into our communities overwhelms the globalists. Make sure no one wants to be one of the parasites giving up months of their lives in an effort to overwhelm us.
It would be interesting to see what countermeasures would be employed to counter the drones.
Some would say KILL the tunnelers; but those diggers are enslaved by folks south of us to do the actual digging.