Viewpoint diversity reduces a community’s susceptibility to witch hunts. One of the most important kinds of viewpoint diversity, diversity of political thought, has declined substantially among both professors and students at American universities since the 1990s. These declines, combined with the rapidly escalating political polarization of the United States (which is our focus in the next chapter), may be part of the reason why the new culture of safetyism has spread so rapidly since its emergence around 2013.
