I think that Berkley's Diversity Oath is not excluding people based on ideology, but rather based on their ability to do the job.
Berkley seems to have taken the stance that part of being employed at the university means making contributions to diversity, equity, and inclusion. The self-authored vow is the way they choose to evaluate candidates on their ability to perform these tasks.
You could argue that making contributions to diversity shouldn't be part of the job description, but this seems like a much harder angle to argue. Then again, maybe in the 1950's the same seemed true of being anti-communist...
Berkley seems to have taken the stance that part of being employed at the university means making contributions to diversity, equity, and inclusion. The self-authored vow is the way they choose to evaluate candidates on their ability to perform these tasks.
You could argue that making contributions to diversity shouldn't be part of the job description, but this seems like a much harder angle to argue. Then again, maybe in the 1950's the same seemed true of being anti-communist...