I don't doubt that liberals and conservatives still interact within the community; my point is that the interaction isn't occurring in the public sphere, where it is needed. Instead, both sides seem to be doing their utmost to shoehorn the motives of the other half of the population into a box. That is how it looks from outside the United States, at least. Not a regular reader of the NY Times so I couldn't give you an informed opinion about Friedman either way. I'm happy to accede to your perspective.
By "public sphere" you mean the media. The media in this country are a disaster thanks largely to for profit, publicly traded news being the overwhelming source for most people. If it looks like liberals and conservatives don't interact to the rest of the world, it is wholly the result of the media concocting and exporting a story they find compelling. Politicians, most of whom are egomaniacs, love this narrative, because it give them them the feeling that they are like a sports team that gets to have a cheering section.