Again, the measure of a democracy isn’t whether authoritarian-leaning politicians challenge the system—it’s whether they ultimately succeed in undermining it. Roosevelt, McCarthy, and Nixon’s failures show why democratic norms act as “guardrails.” All three men pushed up against the guardrails by tempting other politicians to choose intolerance, play hardball, and put party over country. But those other politicians didn’t take the bait. Still, Levitsky and Ziblatt emphasize that, in the U.S., political harmony has long depended on the anti-democratic norm of racial exclusion, as well as the democratic norms of toleration and forbearance. In the 21st century, they argue, the U.S. has to repent of this “original sin” and create a functioning democracy based on the norm of racial
inclusion instead.