Yes; few realize how sharp the urban/rural political divide is.
It doesn't take a full civil war, the 3%, or the Oath Keepers to shut down a city with cold/hunger. How many truckers/farmers would it take to disable the interstates into and out of a major city? A small number of large vehicles permanently disabled and blocking the shoulders and traffic lanes, inbound and outbound, perhaps even chained/welded together to delay towing even once they could be reached, would do it. Throw in the traffic stuck behind them, perhaps a second group of large vehicles blocking the stuck vehicles from being driven out backwards, and by the time the large vehicles could be removed, the traffic jam behind them would no longer have drivers.
Anyone who wants to steal an election would have to contend with extreme, widespread, just-in-time-inventory hunger. I don't think enough of America's enemies are desperate enough to try that. Yet.