Not much of a precedent, in my opinion.
The logistics have completely changed in the last 150 years.
The hated 'fly-over' country is who feeds America, and produces what goods we produce anymore. It's where stuff gets done. Talk about stepping on your crank, to attack your logistics tail.
Be best we never have to find out.
/johnny
Myself, I've got this topic pegged as little more than a bull session. All those resistance advantages mean that any attempt to impose a dictatorship would be short-lived. Unless Fate has a gigantic Black Swan a'waiting, one that none of us can hope to forecast, any attempt to impose a dictatorship on America would collapse of its own accord quickly.
As for the Dems, they're quite used to gaining and keeping power through elections and counting on their own boys to "nudge" things when the electorate repudiates them. Why would the libs even take the risk? If there's one rule in life, it's this: the King of the Mountain is least likely to tear down the mountain, because he'll imperil his Kingship.