This article points to an interesting historical trend which has only occurred four times in the last century. While the argument seems plausible on the surface, I do think that the article misses a bigger picture. The pendulum swings of the American population are always there, and while yes they were greater in those four particular times, it is not all that this article is cracking it up to be.
America is disillusioned with politicians, that is true, that's part of the reason why the people are turning their backs on the current administration. This administration reflects a total disregard for the will of the American people, and as such the people are not going to tolerate it. The administration thought that it could hood wink the American people, and that it would not suffer the consequences therefrom, however reality is beginning to set in.
Far too many times Obama has crossed over a line which he never should have. The most recent of which was calling Republicans enemies. This is a reflection of how he really feels towards those who stand in opposition to him, and also reflects the tense nature that he has forced America into.
I honestly cannot say that this is something of America oscillating between two extreme political spheres, rather America is tired of politicians who pander to illegal aliens, who cannot reign in out of control spending, and who continually lie to the American people. Honesty is a virtue to which too few politicians are accustomed to. As a result America is turning back to her key philosophies in such movements as the Tea Party. We are doing these sorts of activities, because the government, and those within the government, have forgotten their rightful places, and have for far too long overstepped their boundaries.