The Southern border is wide open....except for the few hundred feet of "adequate" fencing and the Rio Grande which is easily crossed in spots.
The biggest problem is the DROVES of people lying their a**** off when they get caught.
Ha ha you think the great lakes are a moat. Cute. There are millions of boats on those lakes and loads of inlets and waterways to smuggle cargo. Prohibition didn’t work in that area because its damn easy to smuggle by boat.