The United States' culture is abnormally polarized [1] now in the 2010s. It is principally bi-polar, having two heads: Red America and Blue America [2]. America has always had two heads (see belief tacking → below), except for a very brief period of time in its infancy when it had three. This by itself is not a concern, but rather the depth and quality of the division between the heads is. When the division is deep, each side becomes siloed and separated from the other (AKA "echo chambers") which makes it opaque → across the line of division. When the division is antagonistic, each half wastes its resources attacking the other rather than accomplishing productive work.
[1]Ideological conflict is vitally important for institutional development. Where conflict exists is a good indicator of what unresolved issues remain. Conflict also allows an institution to engage in self-criticism, and to reflect on its state in the world.
[2]The heads are very deliberately called `Red` and `Blue`. When reasoning about this divide, I often see other terms thrown around, like `conservative` and `liberal`, or `left` and `right`. I have found these other terms to be essentially false; both Red and Blue America have their conservative and liberal components, their left and their right, etc.
From the perspective of Red and Blue, they are each engaged in a struggle for domination against their peer, their equal, and in light of their antagonistic relationship, their arch-nemesis. From the perspective of America, it is engaging in an act of suicide. By inserting its hands into its own mouth and pulling violently in separate directions, it hopes to tear itself limb-from-limb. Needless to say, if it is successful, it. will. die [3].
[3]In case you harbor any delusions that Red and Blue can get a divorce, the two are too deeply interconnected to be able to maintain themselves separately. To use the bodily analogy, one side will take the stomach, and the other will take the liver, and then they shall die of lack-of-stomach and lack-of-liver respectively.
The causes of this divide include a factor from all the bullet points under polarization →.
The rise of the information economy, by enabling individuals to find and keep like-minded friends and peers, has changed the topology of an individual's relationship with their neighbors so that it is easier for them to choose their neighbors, and specifically to choose like-minded ones. This facilitates schizophrenia, because relationships that have higher differences are cleaved rather than normalized. This cleavage resembles partitioning.
Cultural war, obviously. Red and Blue both have taken to using their othered peer as a proxy for evil incarnate.
America faces a great decision, and it is somewhat split over what to do. This decision is not driven by a crisis, but rather the lack of one: America doesn't know what to do with itself. It has broadly accomplished every external-facing challenge it has ever put itself to, but in the lack of such a challenge, it lacks direction. Red America has generally moved towards solutions that re-establish or re-new American dominance over the external world. Opinions of American supremacy are common, as are appeals like "make America great again". Blue America has generally moved towards solutions that denigrate or seek to dismantle American dominance over the external world. Opinions of American inferiority are common, as are revolutionary appeals.
It's worth also noting some differences between Red and Blue with respect to their own internal organization. Blue America is decidedly more normalized, and it's larger trend is towards totalitarianism. Red America on the other hand is decidedly more schizophrenic, and it's larger trend is towards anarchy.