If considering the landlord biz, I think you'd want to see the percent of renters vs homeowners among registered voters.
The greater the majority of voters who are renters, the greater the chance of legislation and taxes than homeowners - and, by extension, landlords - may consider to be not in their interests.
I couldn't find a comprehensive list, but a partial list is here and you could dig the info out from Census data or perhaps real estate industry sources.
https://insurify.com/insights/cities-most-renters-2020/