A violent coup would be very unlikely in the US, if for no other reason than Large Industry would put too much pressure on the Government before that point. If a situation arose where they saw the profit-margin of their US interests at risk, they'd start applying political muscle.
The problem is that the voters believe that simply complaining is enough, and the Industry are happy to keep things that way, as long as people still buy their products. If everyone in the US decided, for example, to refuse to buy, say, an SUV until they improved the fuel economy on it, something would get done about the fuel economy. There's no point producing a product that won't sell. But we live in a world where people will complain about the cost of luxuries, and yet still buy them.
