The primary problem is the cost of energy. Until we innovate away from an fossil-fuel based economy, then this mode of transportation will be accessible only to

The primary problem is the cost of energy. Until we innovate away from an fossil-fuel based economy, then this mode of transportation will be accessible only to the very wealthy. It will probably require the invention of nuclear isomer batteries to make it affordable to the masses. As for sociopolitical factors, well it might not matter at all at the rate we're going. As soon as a suicide bomber gets hold of a nuke, it's pretty much all over. From then on martial law will be the rule of the land(s), and no one will be doing much of anything.