This is not the first time that everyone is screaming about the doom and gloom of US economy and its standing in the world, it happens once in almost every decade. While I don't agree with the author's choice of hyperbolic words but I don't see any reason why USA can't get back to its way of dominating the world economy.
I am not an economist so I could be wrong. But I also know that economic predictions by some of the best economists in the world has been as good your local whether channel guy. So when they all cry about how US is going down in flames, it makes be a little happy knowing that how often they are wrong about everything.