#Load libraries
library("sandwich")
library("lmtest")

#Load Data
data <- read.csv("C:/Users/Benja/Downloads/2008V2020Difference.csv" , header=TRUE, sep=",")

#Run ordinary least squares
ols <- lm(Difference ~ Dominion,  data = data)

# Test non-weighted regular standard error
summary(ols)


# Test non-weighted robust standard error
coeftest(ols, vcov = sandwich)


# Run weighted least squares
wls <- lm(Difference ~ Dominion, weight = TotalVotes,  data = data)

# Test coefficent using regular standard error  
summary(wls)

#Test coefficient using robust standard error
coeftest(wls, vcov = sandwich, cluster = ~ TotalVotes)