This is not to say that McCain or other “old school” politicians were unwilling to go negative or attack their political opponents. They would and did. It’s that there were lines they wouldn’t cross—especially when it came to respecting the legitimacy of their opponents and of journalists. These are lines that politicians like Palin and President Trump won’t even acknowledge. And in a big, diverse democracy, where power is transferred peacefully, where compromise and consensus are required to get things done, those boundaries matter.

Another corrosive trend: Palin’s contempt for experts and elites. The then-governor didn’t study policy journals or even follow national news. She resisted when McCain aides tried to get her to focus on preparing for our interviews. But she thrilled her supporters with attacks on coastal liberals and support for “normal Joe Six Pack Americans.” Among some conservatives, a disdain for the liberal intelligentsia morphed into a disdain for the highly educated or for facts that contradicted their worldview. That has led to the current environment, where no matter what evidence the experts have brought to bear—against Brexit, against Trump’s trade and tax policies—it doesn’t matter to many voters. These elites, and the arguments they make, are dismissed out of hand.

One last lesson from covering Palin: Women who run for national office are treated worse than men. This is unsurprising but worth examining. Palin was obsessed with her image and coverage—even forcing the cash-strapped McCain team to spend money on a poll in Alaska, a GOP stronghold, because she was concerned about her popularity back home. But Palin wasn’t wrong to worry that she was being held to a different standard.