The relevant article is found here.

In it, Reilly says he built a regression model with covariates as population [number], population density, median income, median age, diversity (measured as the percentage of minorities in a population), and the state’s Covid-19 response strategy (0 = lockdown, 1 = social distancing).

#import data
library(haven)
df <- read_dta("./COVID.dta")
attach(df)
head(df)
## # A tibble: 6 x 10
##   StateName Population Density   Age Income   POC Strategy Cases Deaths Governor
##   <chr>          <dbl>   <dbl> <dbl>  <dbl> <dbl>    <dbl> <dbl>  <dbl>    <dbl>
## 1 Alabama         4.90   93.5   39.9   48.1  31.5        0  4241    123        0
## 2 Alaska          1.30    1.30  34     73    33.3        0   293      9        0
## 3 Arizona         7.30   57     37.4   56.6  27          0  3692    142        0
## 4 Arkansas        3      56.4   37.9   45.9  23          1  1599     34        0
## 5 Californ…      39.5   254.    36.3   71.2  27.9        0 26838    864        1
## 6 Colorado        5.80   52     36.6   69.1  18.7        0  8280    357        1

ANOVA strategy — States form blocks and within each block is a independent variables (which can be viewed as treatments) which produces a response variable deaths.

lm1 = lm(Deaths ~ Population+Density+Age + Income + POC + as.factor(Strategy) + Cases)

anova(lm1)
## Analysis of Variance Table
## 
## Response: Deaths
##                     Df    Sum Sq   Mean Sq   F value    Pr(>F)    
## Population           1  17581158  17581158  799.0221 < 2.2e-16 ***
## Density              1   9454264   9454264  429.6740 < 2.2e-16 ***
## Age                  1     27814     27814    1.2641  0.267269    
## Income               1      4320      4320    0.1963  0.659985    
## POC                  1    269539    269539   12.2499  0.001116 ** 
## as.factor(Strategy)  1     81564     81564    3.7069  0.060977 .  
## Cases                1 110944053 110944053 5042.1453 < 2.2e-16 ***
## Residuals           42    924140     22003                        
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1