Biggest meme of the week:
http://www.independent.co.uk/news/world/americas/north-korea-us-attack-emp-power-grid-kill-90-per-cent-american-population-electromagnetic-pulse-a8002756.html
Are all americans robots, or how the hell are 90% of all americans going to die by shutting down the power grid?
I envy your ability to be oblivious of your dependance on the power grid
While it certainly would be more difficult without a power grid, not all electronic devices will be rendered completely useless due to an EMP attack.
Most vehicles and especially heavy and older trucks will be able to resist an EMP attack too. This means, while it would be more difficult to transport food around, it would still be possible. It is also not like you can not repair stuff after an EMP attack.
Getting fuel would be the most difficult task, as most pumps in fuel stations will break, but since fuel is one of the most important things, I am sure people will quickly set on repairing those, to make sure that goods and people can be transported around.
90% seems way to high. Sure people would die, most likely people would also starve due to food shortages, but 90% is ridiculous.
Besides that, how the hell are you supposed to kill the entire US power grid all at once.