As to the route this fellow took, wouldn't it make sense to ban passengers carrying passports from Ebola hotspots?
The current administration would prefer nonsense, thank you.
So you close off the airports in Liberia for example. Folks got frustrated at this treatment...so they take a bus over to Togo, and fly out there to Morocco, then onto Madrid, and then onto Miami. Figure a two-day ride on a bus...sit around at the Lome airport for eight hours for the flight, and you can be in Miami area within five days.
You basically would have to close off the whole of central Africa, and I doubt if this would really work. The only alternate and reasonable deal is a holding pattern at US airports and stall folks for a number of days in some quarantine situation. Folks would get hostile over a cot and some bowl-of-soup situation with guards at the doors holding you in some marginal camp situation.
This guy had a visa. Liberia has a high rate of people who overstay their visas. You have to wonder what kind of judgement is being used to issue visas to 40 year old single, unemployed men from Liberia.