Breaking GDP growth by POTUS demonstrates the Great Depression skew even more significantly. Let’s have a look by President, starting Wilson’s years after WWI:
There’s something here for everyone to like. The Depression skews are clearly seen on the two outliers, FDR and Hoover. Remove those, and LBJ and Harding are in a virtual dead heat for the lead; LBJ ran a Keynesian presidency, Harding a supply-side one. The Dems take three of the next four spots, but also the bottom two; Republicans tend to show a more consistent pattern of moderate growth when they are in power, avoiding the volatile swings that induce economic uncertainty. From this, it’s easy to see how the full data favors the Democrats, but also how the Republicans “tie the race” we move closer to the present day.