Flint, no.

The device needed to create a REAL electromagnetic pulse (one we would need to worry about) is... you guessed it... a simple Hiroshima-sized nuclear weapon.  The only difference is where the weapon actually explodes.  A nuclear missile hitting New York destroys New York.  A nuclear missile exploding hundreds of miles in the air creates an EMP that basically uses the upper layer of the atmosphere as a lightning rod to spread.  Multiple military and physics scientists have estimated that, when launched at the correct area of the country, an EMP could shut down the entire continental United States (Granted, that area is deep inside the US.  It would probably be more likely that a missile would be launched off the East coast and take down a huge region of the country).