Geographical party preferences by state during Mexico's presidential elections

The present analysis uses presidential voting data from the Instituto Nacional Electoral. It contains the votes obtained by each party or coalition during the 2012 presidential election. The data set contains the votes registered in each of the "voting districts." I am interested in showing the distribution of electoral preferences for each party-coallition over the country. I aggregated the votes for each state and coalition and plotted them in a map of Mexico. I normalized the per-state vote count by dividing each state's votes by the nominal list (number of registered voters for the state). This is done in order to show a meaninful geopraphical distribution of electoral support and remove the bias due to state population. This gives us the number of "per voter votes" in each state and we can obtain the percent contribution from each state. I color coded the percentage of per-voter-votes obtained in each state A darker color means higher percentage of votes (normalized by state population).