I don't think they would use an EMP.
Think about it. That destroys their entire power base. They control their lemmings through MSM and the internet (Big Tech), through their cell phones, tablets, smart TV's and computers. An EMP removes their own sources of control and manipulation.

I think it's far more likely that they will double-down on causing widespread deaths, fear and panic. Release deadly illegal drugs in U.S. cities that will cause drug users to die in large #'s. Dump caches of automatic weapons into gang areas of cities. Do whatever it takes to cause panic and fear among the populace. That will make MORE people tune in to MSM and the internet to get the latest news. The Deep State then controls the messages they hear.

That would be a more likely scenario. Fear of an EMP or nuclear attack also works to scare people into watching MSM or internet... so the lemmings can all be programmed.