This is yet another illustration of the fact that electoral politics are a modern version of witch hunting - the main purpose of both activities is to find acceptable scapegoats for maladies whose causes are poorly understood by the populace.
This is a general tendency not limited to the US and it can be observed in many countries, from India to the EU. The economy tanks and the populace "punishes" the current government by voting it out, as if it were solely responsible for workings of the market system. It matters little that the guys that are voted in pour more gasoline to the fire by giving more free reign to business interests that created the problem in the first place. The workings of the market system remain a mystery to the modern populace just as diseases or weather were a mystery to the medieval populace. In both cases the primitive mind imagines that disasters are willed by powerful individuals. All that matters is to attribute the blame to an acceptable scapegoat - witches in the dark medieval ages and governments in the equally dark modern ages - and punish them in a public spectacle for the rabble.
Disgusting.
Wojtek