How you whip up hatred and distrust has never been much of a secret. More than 50 years ago, Jacques Ellul, in his landmark book Propaganda, wrote, “Those who read the press of their group and listen to the radio of their group are constantly reinforced in their allegiance. They learn more and more that their group is right, that its actions are justified; thus their beliefs are strengthened.” Substitute “tweets,” and “memes” and you have social media today, in which an algorithm feeds you the information that you are likely to click on—because you have clicked or retweeted or reposted something just like it (see Technology). The techniques that once worked on TV and radio have been supercharged by micro-targeting. This is not merely an echo chamber: It’s a pinball machine, into which manipulators cynically drop memes—the Black Panthers support the Democrats!—to bounce around and amplify.
The government of the United States was constructed, as James Madison wrote, “to break and control the violence of faction.” Now faction is ascendant, and it is the union that is breaking. There are no more big tents. Centrist Republicans such as Bob Corker and Jeff Flake have quit politics; centrist red-state Democrats Claire McCaskill and Heidi Heitkamp didn’t survive Tuesday’s vote. In Congress, it becomes harder for elected representatives to do anything but vote in lockstep with their parties. When Donald Trump was elected, it was said that he had “broken” the Republican Party. The opposite is true: The parties are stronger than ever. Except now party loyalty is enforced by your own friends and acquaintances, who will make sure you don’t step out of line on Twitter or Facebook. That’s something autocrats and demagogues of the past could only dream of. How else can the dark powers of social media be manipulated and misused? In the coming two years of divided government, we will most likely find out.