Ever since the infamous “red vs. blue” map of the American electorate that emerged during the last election — a color division with, I might note, unintentionally hilarious subtextual references — pundits have claimed that the US is a country divided. In one corner, we’ve got the snarling Republicans, devoted to church, the family, lower taxes and the war on Iraq; in the other corner are the Democrats, growling about presidential deceit, the deficit, giveaways for the rich and nonexistent WMDs. Is there any middle ground?

Possibly, if you believe the network theorist Valdis Krebs. He conducted an interesting experiment to find out who was reading what. He took all the rabidly political books off the New York Times’ bestseller list and plugged them into Amazon and BarnesandNoble.com. Thanks to the “readers who liked this also bought” feature, he was able to see what other books the readers had bought or browsed.

The result? A map of the nation, showing that — whaddya know — readers of left-wing books tended to read only other left-wing books, and readers of right-wing books other right-wing books. As the Times’ Emily Eakin reports:

His map showing how the titles are connected by buyers reveals a readership — or at least a book buyership — as fiercely polarized as the national electorate is said to be. On the left is a cluster of several dozen liberal polemics (the blue nodes) linked by a dense thicket of crisscrossing gray lines. On the right is a nearly identical cluster of conservative tracts (the red nodes). Connecting the blue and red sides of the map are just a few gray lines and gray nodes, all politically moderate or nonpartisan titles, including Sleeping With the Devil by Robert Baer, Bush at War by Bob Woodward and All the Shah’s Men by Stephen Kinzer, a cultural correspondent for The New York Times.

Go check out the story and you’ll see the entire map. But what interested Krebs’ mostly were the very few books in the middle — like Bush at War and Sleeping with the Devil. Possibly, he argued, these represent those rare talking points that might bring the country together:

“It’s through those books that people can get to both sides.” Or, as he puts it on his Web site, www.org net.com: “See someone reading `Sleeping With the Devil’? That is someone you can talk to about your candidate.”

Me, I don’t entirely buy it — or more precisely, I don’t entirely care. I’ve never entirely understood the punditocracy’s concern for “partisanship”. What the hell is wrong with partisanship — with people fiercely believing things and fighting for them, and disagreeing vehemently with other people about them? The pundits behave as if the ultimate goal of all political life is to have the parties in smooth, frictionless agreement with one another. What’s so great about that? A world in which all your political leaders have one political opinion? Last time I checked, they had names for that: Fascism. Actually, totalitarianism works nicely too. All the leaders in China and Cuba agree with one another, but that doesn’t make them terrific polities. This we-must-agree-at-all-costs attitude is even more bizarre coming from citizens of a country the political spectrum of which is barely wide enough to support two parties, let alone the three or four or five of most other modern nations.

The problem isn’t that the map is divided into red and blue. It’s that it isn’t also divided into green and yellow and orange.