We don't even have to go that far to realize how quickly the democratic establishment would roll over in the face of a civil war. I don't think Chuck Schumer is going to be leading an armed resistance movement anytime soon.
They have to accept cash in the US as well. The post you're replying to is just saying that they can't ring anything up or accept any payment without power.
A president who is willing to do those things, and has a military willing to carry those orders out, isn't likely to be stopped by the court telling them it's illegal.
Yeah GTA doesn't have much in terms of destructibility. Some of the battlefield games do this pretty well though, particularly Bad Company 2. It was very common in that game to use explosives to make different ways in and out of buildings.