We’re still debating whether Russian bots, fake news and inflammatory Facebook posts tipped the 2016 election—but there’s something much more fundamental at work here: America’s political culture is deeply sick, and ripe for exploitation.

The reason so many Americans believed the vitriolic Russian posts is that they resembled vitriolic American posts. If the context of polarization and online hostility didn’t exist, the Russian posts would have stood out as conspicuous forgeries, even given our level of news illiteracy. You don’t impersonate someone by saying something he wouldn’t say. The voice the 13 Russian ventriloquists—the ones the special counsel indicted last month—threw was our own.

When such posts come from trolls and bots in Russia, they’re illegal, as they should be. But when they come from U.S. citizens, the damage is largely the same, even if there’s no chess-master manipulating a focused attack. Granted, the Russians’ intention was the opposite of the cable news outlets, the radio hatemongers, and most U.S. citizens. If democracy is a marriage, they wanted to lure us toward bitter divorce, or perhaps a murder-suicide, whereas those of us motivated not solely by likes or Nielsen ratings want to save the marriage by winning key arguments. But we’ve become like bitter spouses at a dinner party, insulting each other publicly, forgetting that we have to go home together, and that the tone of what we’ve said will linger far longer than the content.