On the whole, I really have to agree with Selil's analysis.

So whereas many might see this hyper-politicization process as a negative in many ways it is increasing the access to ideas. The behaviors negative and positive including the near fascist and far leftist opinions of ideology show that homogenized content is a thing of the past. The task is to not fall into that trap and provide for open dialog and use the same tools to communicate as much literal truth (as you see it) possible. Then with credibility your ideas will inoculate the population against malfeasance and manipulation.
Selil, have you, by chance, looked at Dawkins meme theory? I am asking, because I'm really in doubt that "sanity" (read as communicating a literal "truth") is as contageous as "insanity" (read as a reasuring, ultimately BS, belief).

Zenpundit mentioned Turner's use of geographical determinism, at least as far as general cultural traits are concerned, and I have rapidly been coming to the conclusion that a similar form of determinism operates in cyberspace - "geographical" only in the social networks sense and measured in cross-linking rather than miles or km. I remember analyzing a series of bulletin boards back in the late 1980's, and there was a really heavy correlation between board/thread linkages and memes describing assumptions of opeartional reality that appears to be true even now.

I certainly do agree with you that the increasing popluar availability of content generation is producing many differing viewpoints but, I would also suggest that this content tends to converge into virtual "islands" with heavy interconnectivity. It is pretty rare, in my experience, to find many people who are members of two or more online communities that share mutually opposing basic conceptualizations of reality.

On the hyper-polarization issue in US politics more generally, I really have to wonder if it doesn't stem from two structural factors as well. First, you seem to have settled on a two party system ever since your civil war (Teddy Roosevelt's BullMoose party, along with Ross Perot, excepted). I honestly don't see how any two-party dominated political system can be anything other than "polarized". While I would never argue that our (Canadian) system is actually better or more efficient than yours (I wouldn't even know what criteria to use for the comaprison), I think that our multiparty system has the "benefit" of forcing our politicians into a somewhat less polarizing format, especially in minority government situations such as we currently have.

Second, you actually elect your head of state in a party-based fashion. As far as I can see, this would inevitably lead to polarization either in the process of government (e.g. when the president is from one party and congress and/or the senate is dominated by the other) or in the time mandated election system you use (when all houses are controlled by a single party). To my mind, this inevitably leads to a situation where it is structurally mandated that your head of state must be attacked which would, inevitably, lead to cries of "treason". Personally, I prefer the Canadian/Britsh system where our head of state is the Crown (and pretty powerless on the whole) and our head of government is merely a politician we can laugh at and call an idiot with no taint of treason. It has certainly served us well in the past

Marc