To find political tolerance, seek religiously affiliated universities. For partisan homogeneity, seek public institutions.

From Faculty Partisan Affiliations in All Disciplines: A Voter-Registration Study by Christopher F. Cardiff and Daniel B. Klein.

ABSTRACT: The party registration of tenure-track faculty at 11 California universities, ranging from small, private, religiously affiliated institutions to large, public, elite schools, shows that the “one-party campus” conjecture does not extend to all institutions or all departments. At one end of the scale, U.C. Berkeley has an adjusted Democrat:Republican ratio of almost 9:1, while Pepperdine University has a ratio of nearly 1:1. Academic field also makes a tremendous difference, with the humanities averaging a 10:1 D:R ratio and business schools averaging 1.3:1, and with departments ranging from sociology (44:1) to management (1.5:1).Across all departments and institutions, the D:R ratio is 5:1, while in the “soft” liberal-arts fields, the ratio is higher than 8:1.These findings are generally in line with comparable previous studies.

Nothing really new here. It is well established and long established that universities in the US suffer an extreme ideological imbalance that is also unreflective of the at-large population.

What caught my attention were the five universities that came closest to a partisan balance. Two religiously affiliated universities Point Loma Nazarene University and Pepperdine University had the closest to a representative partisan ratio of Democrats to Republicans with ratios of 1.0, 0.9, respectively. In other words, counter to stereotypes, religious universities were the most politically diverse in the California sample and the state institutions (with a greater obligation to support diversity and to reflect the demographics of the state) were by far the most unrepresentative with ratios of between 7 and 9 Democrats for every Republican.

The stereotype is of religiously affiliated universities being more dogmatic and hewing to a particular belief system and less tolerant of those who depart from the orthodoxy. This is a great example of measurement refuting stereotypes or of measurement disabusing us of illusions. From this small sample, it appears that religiously affiliated universities are actually the ones that are most philosophically diverse and tolerant.