Of relevance to that which drives threats to free speech.
Tolerance: “a willingness to permit the expression of those ideas or interests that one opposes.”
A review of social science work on political tolerance/intolerance especially on university campus
https://heterodoxacademy.org/the-skepti ... -are-high/
Abstract: A series of essays published in March argued that American college students are just as supportive of free speech as they have ever been, so there is no “free speech crisis” on American college campuses. In this essay we show that this optimistic reading of the most widely used longitudinal dataset (the GSS) greatly overestimates political tolerance because of a methodological artifact: it asks about speakers that are not very controversial anymore, such as a “communist” or a “homosexual.” When we examine data about speakers that are strongly disliked today, we find much higher rates of political intolerance, particularly among college students on the left. We argue that this political asymmetry tells us nothing about the left or right in general, but rather about who is feeling psychologically insecure in the last few years. We think these re-interpretations of the GSS, along with an analysis of two recent datasets, undercuts the skeptics’ main argument and contradicts their thesis, while pointing to productive new ways to address the conflicts roiling many campuses.
... [Relative to attitudes in the 1950s ] Speakers who are regarded as homophobic, transphobic, or Islamophobic can be thought of as the communists or atheists of today. They are the most intensely disliked, particularly, it seems, on college campuses. If we want to know whether college students are more tolerant today than they were in generations past, it makes little sense to ask them if they’d tolerate a communist, an atheist, or a homosexual making a speech. The rising lines of tolerance in Figure 1, using the Stouffer method, do not show that young people are becoming more tolerant of speech across the board. Rather, an approximation of the least-liked groups method suggests that students on the left are intolerant toward many speakers, particularly those who, presumably, are seen to violate their core values (see e.g., Graham & Haidt, 2012). Most of the groups that current students––particularly liberal students––would consider disinviting are linked to bigotry, but notice that the “anti-feminist” is not anti-woman; the speaker is opposed to feminism, a family of political/intellectual movements. Nearly half of the very liberal students surveyed said that such a speaker should not be allowed to offer such critiques on campus.
One might argue that the speakers opposed by the left are objectively worse than the speakers opposed by the right. It is likely that students on both sides believe–and can explain–why the speakers they dislike are uniquely awful and dangerous ...
... PUTTING IT ALL TOGETHER: WHAT IS CHANGING AND WHY?
The skeptics tell a story of high and uniformly rising tolerance on college campuses. They offer a narrative in which all is well for free speech on college campuses, and that those who raise alarms are engaging in a “moral panic”––an over-the top alarmist frenzy, fueled by right-wing media. We agree that the right-wing media is now doing what it can to raise alarm, and that it often exaggerates or distorts events on campus, but that does not mean that all is well on campus.
...Based their review of the scholarly literature and on maximum likelihood confirmatory factor analysis ... of a data obtained from a national sample, Sullivan et al. (1982) proposed the model [see below]. This model has stood the test of the time, although there remain some “enigmas of intolerance”
NOTE: The paper includes a longer discussion of these factors which I have not quoted here
we have drawn on political science work from the 1980s to offer an account of exactly why political intolerance may be increasing on the left on college campuses in recent years: because more and more students are feeling psychologically insecure, losing faith in democratic institutions, and facing (or at least hearing about) real threats from off-campus right-wing sources.