Decision MediaWorks

Ideal Habitat for Florida Dems: By The Numbers

If you are into political prognostication, it can be useful to look past simple voter registration statistics and into the demographic stats that drive partisan performance.

For this experiment, we wanted to see what single demographic measures most impacted the performance of legislative Democrats.  To find the answer we looked at every Democrat in a Florida legslative general election from 2008 to 2012 and evaluated over 100 different demographic variables from each legislative district.

The decision tree diagram below is the result of our analysis. It starts with all 235 general election races and filters them down based on which factor produced the most winning or losing Democrats – that is, which factor best split the winners and the losers.

For example, our first split is with black voting age population. We find that if the district has >15% black voting age population, Democrats won 90% of the time. If the district had <15%, Democrat won 23% of races. The tree then branches down to the next tier which you can see in the diagram below.

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