What they should do is have the military set up a drone patrol just like over Afghanistan, with rockets, and blast anyone who enters the 'Death Zone' which would be about a 5 mile wide swath along the boarder, too far to tunnel under. Take out a few drug convoys and that stuff will stop pretty quickly.
The cayotes will just charge more and fly them to Canada where they can cross freely... or we'll have to build a 10' wall across that border too?
Or they can just sail them off the coast of Brownsville, TX up until there is a quiet beach and dump them off...
I posit that the walls around Israel/Palestine have done a LITTLE to stem all the nonsense over there (tunnels, ladders, corrupt checkpoint folk) but have not really eliminated the problem.
And for the economic migrants, I can almost understand why they'd risk it to earn 10x as much as they could in the US (and send it back so when they return they can retire).
It is sad that our immigration policy is so restricted they have to consider illegal crossing (which bars them from free travel back and forth so they're stuck in the US if they cross successfully).
Would you rather have a bunch of illegal immigrants stuck in the US ( and collect social benefits - housing assistance, SNAP, etc) or "green-card" migrants who can leave when they're done with the work? I believe the green-card folk have to pay taxes, don't get Social Security, and have to return to their home country in order to renew the permit.
