The original intent of this plot was to explore election victory margin and presidential rating, with the idea being that higher rated presidents should have been voted into office on a higher margin of victory. After some additional thinking, I realized that the original premise was flawed - every presidential election should be treated as a contest of its own, between the two contenders, and can't really be held in comparison to other elections. However, it was still a fun data scraping and visualization exercise. The results of the exercise are in the visualization/code seen.

Each presidential election has been shown, plotting margin of popular vote victory against a ranking of the Presidents' effectivness (data from the 2014 American Political Science Association’s Presidents & Executive Politics ranking of American presidents). There's a 0.15 Pearson's r correlation between margin of victory and presidential ranking. If I'm to draw a conclusion based on a flawed premise, it'd be that the American people are rather poor at picking presidents. I think a more interesting investigation would be one comparing data across different styles of ruling - democracy, communism, and dictatorships - and trying to find a metric to compare them. That will have to be for next time.