The Manhattan Institute* has a lengthy report on the increasing homicide rate, Breaking Down the 2020 Homicide Spike by Christos A. Makridis and Robert VerBruggen (5/18/2022), with numerous interesting charts. From the report (figure 7 copied here):

Next, we explore the correlation between two geographic factors—population and GOP vote share—and the growth rate in the homicide rate per capita between 2019 and 2020. Each observation is a county whose size is determined by its population, giving larger counties greater weight. Counties with a higher share of GOP voters not only have lower homicide rates but also a lower growth in homicide rates between 2019 and 2020 (

Figures 6and7).There is a positive correlation between population in a county and the

growthin the homicide rate, but the correlation between population and just the homicide rate is slightly negative (Figure 8). In this sense, even though there are slightly higher rates of homicide deaths per capita in smaller counties, some of those differences could be driven by spurious factors that are correlated with population.

There is a lot to discuss in this article as well as ample quantitative literacy material. There is a discussion of methods and the CDC data they use is easy enough to locate.

* Yes, MI has a clear political leaning but that doesn’t make their work incorrect. Their data and methods are sound here and this should be engaged not ignored. If someone thinks something is incorrect then let me know.