prrace08: Election results for the 2008 U.S. Presidential race
In usdata: Data on the States and Counties of the United States

Description Usage Format Details Source Examples

Election results for the 2008 U.S. Presidential race

prrace08

A data frame with 51 observations on the following 7 variables.

state: State name abbreviation
state_full: Full state name
n_obama: Number of votes for Barack Obama
p_obama: Proportion of votes for Barack Obama
n_mc_cain: Number of votes for John McCain
p_mc_cain: Proportion of votes for John McCain
el_votes: Number of electoral votes for a state

In Nebraska, 4 electoral votes went to McCain and 1 to Obama. Otherwise the electoral votes were a winner-take-all.

Presidential Election of 2008, Electoral and Popular Vote Summary, retrieved 2011-04-21.

#===> Obtain 2010 US House Election Data <===#
hr <- table(houserace10[,c("abbr", "party1")])
nr <- apply(hr, 1, sum)

#===> Obtain 2008 President Election Data <===#
pr   <- prrace08[prrace08$state != "DC",c("state", "p_obama")]
hr   <- hr[as.character(pr$state),]
(fit <- glm(hr ~ pr$p_obama, family=binomial))

#===> Visualizing Binomial outcomes <===#
x  <- pr$p_obama[pr$state != "DC"]
nr <- apply(hr, 1, sum)
plot(x, hr[,"Democrat"]/nr, pch=19, cex=sqrt(nr), col="#22558844",
    xlim=c(20, 80), ylim=c(0, 1), xlab="Percent vote for Obama in 2008",
    ylab="Probability of Democrat winning House seat")

#===> Logistic Regression <===#
x1 <- pr$p_obama[match(houserace10$abbr, pr$state)]
y1 <- (houserace10$party1 == "Democrat")+0
g  <- glm(y1 ~ x1, family=binomial)
X  <- seq(0, 100, 0.1)
lo <- -5.6079 + 0.1009*X
p  <- exp(lo)/(1+exp(lo))
lines(X, p)
abline(h=0:1, lty=2, col="#888888")