The only reason there wasn't a pandemic from Ebola up to now was that the previous cases occurred in small, isolated villages that were difficult to get to and where travel back and forth was rare.
Now that it's in a crowded, urban setting it's different. MOST of the population of the US live in crowded, urban settings. Do the math.
It takes more than math for your doomsday scenario to pass muster.
And even with a knife-carrying jumper scaling the WH 7.5 fences and a felon getting into the elevator with the pResident carrying an undisclosed gun, the administrations feels that they can contain Ebola, so it probably will affect us (via the troops sent to contain it in Africa), but somehow won’t affect them. Just like all those pro-Obamacare wonks who lost their insurance, lots of people will be surprised how they underestimated this latest version of an anti-American assault.