'The Grid' can be knocked out...And I move that you don't know what you're talking about; you don't know the inherent relaibility gained by the utilization of the grid topology, and furthermore, it is the continued and wilful ignorance of system operators whether through overlooking of maintenance issues (like tree-trimming or setting of protective relays) and errors in the real-time operation of those systems that lead to collapase.
The 2003 Blackout REALLY showed up what operating a system 'blind' on a hot day can do in conjunction with lax preventative maintenance on the vitally important transmission/intertie systems (read that as 'lines').
Have you forgotten all that in your lust for postus maximus?
Nope. Not at all.
I still submit that any sufficiently motivated enemy can figure out a way to knock out electrical power in most of the USA, either by an overt frontal sabotage attack, or by a more subtle malware attack convincing the operators that everything is just ducky while the automatic systems are frying one component after another.
Time will tell, in the meanwhile there is certainly no shortage of swarthy electrical engineering students being trained in our universities...