Contributions per Candidate

contributions_per_candidate.r

# read csv file
ds <- read.csv('2012-Presidential-Campaign-Finance-Contributors.tsv', sep='\t')

# aggregate by candidate
res <- aggregate(ds$contb_receipt_amt, by=list(ds$cand_nm), FUN=sum, na.rm=TRUE)
X = data.frame(name=res$Group.1, amount=res$x)

# make data columns callable without typing X$ everytime
attach(X)

# sort dataset by amount
X <- X[order(amount),]

# assign party and colors
X$party[name == "Obama, Barack"] <- "Democrats"
X$color[name == "Obama, Barack"] <- "#2255EE"

X$party[name != "Obama, Barack"] <- "Republicans"
X$color[name != "Obama, Barack"] <- "#EE2244"

X$party <- factor(X$party)

# create a nicer labels like "Obama, Barack ($123.4 mio)"
X$labels <- sprintf("%s ($%.1f mio)", name, amount/1000000)

detach(X)
attach(X)

# output dot chart
dotchart(amount/1000000, labels=labels, color=color, groups=party, 
   main="Contributions per Candidate", xlab="Amounts in Mio $", pch=19, cex=.8)

I think I found it here
http://datahub.io/dataset/us-presidential-campaign-finance-2012-contributors@2012-02-04T18%3A12%3A57.428484