Wednesday March 7, 2012
Graph de jour: Romney and Santorum shares of the primary vote cast yesterday in Ohio’s Republican primary, plotted against Obama vote share in 2008. Units of analysis are OH’s 88 counties. Size of the plotting symbol is proportionate to the number of primary votes cast. Lines are smoothing splines in the mgcv package (fits are generated with weights equal to the square root of the number of primary votes). Data from OH SOS.
As the county shades conservative (smaller Obama vote in 2008), Santorum does better. The more the county supported Obama over McCain in 2008, Romney support tends to increase. This is hardly dispositive, but does count as (yet more) evidence of how Santorum will struggle to win the “median voter” in a key state like OH if he were to be the Republican nominee for the November general election.
Fun fact: last person to win the presidency without winning OH: JFK, 1960.
Some other looks at these data. Romney primary vote share (%) against Santorum (%), by county, plotting symbol indicating number of votes cast. Below the diagonal, Santorum beats Romney; above the diagonal, Romney beats Santorum. Romney wins bigger places (urban), more Dems and Indeps, votes that the Republican nominee would need in the general.