I wasn't going to link to this. But then, for some curious reason, I visited the Sunday Funnies and saw a whole lot of unfunny cartoons, mostly complaining about the US's financial disaster, and none pointing to the cause.
So here it is, from Life After Empire:
The average Brit was better off after their ruling class realized they couldn't afford their empire. That will be true in the US, too, if our ruling class doesn't keep ignoring the obvious.