We saw that where they needed to cheat more intensely in order to steal the election were a couple counties in 5 or so states. And as I remember, there was this car-bomb in Nashville that exploded on a AT&T central hub (most likely a NSA surveillance hub) and it brang down mobile phone signal and mobile internet throughout most of the east coast.
No need to nuke the entire system if you just have to put down a central node and the rest falls apart like dominos. What are your guesses ? Mine are all locations of Amazon, Facebook and Google server farms.
Fiber optic cable nodes. Usually in an unsecured cable vault with an unlocked manhole cover. Cut the ones in rural areas which are serving central hubs. Same with undersea cable entry hubs at key near the water locations. This scenario has been discussed for years, with lots of hand-wringing but nothing done to upgrade security.
Drop depth charges on the cables and blame it on Russia