“Neither party can wholly disavow their fanatical fringe. That fringe could, one might wager, be anywhere between a fifth to two-fifths of both major parties. And that means, this fringe is endemic to our politics.

The culprits of our polarization are many. Between 1960 and 2005, one study found that ideological activist groups of all political persuasions increased sevenfold.

Gerrymandering of congressional districts has maximized liberals in liberal districts and conservatives in conservative districts. This has left our congress-people more polarized.

Today, conservatives and liberals can join vacation tours attended by only their side of the debate or join dating services to court only the like minded. At night, one side watches only MSNBC and the other side only Fox News. And when people are around likeminded individuals, one study found, their viewpoints only become that much more extreme…

We are ever more polarized today and so may be the conspiracies. The less each base understands the other side perhaps the more outlandish the theories become, in order explain the hold of the other side.

A few years ago, an Emory psychologist scanned the brains of self-described partisans. Partisans were able to notice the hypocritical statements of the opposing candidate but not the inconsistencies of their preferred candidate. Ideology, it was determined, showed effects similar to drug addiction.”