Maps and Heatmaps: Political Trends

In trying to understand political trends in the U.S., I sometimes default to creating maps. They are beautiful visualizations of voting results. But sometimes maps provide a snapshot of one election or one period in time in a way that does not facilitate viewing trends over time.

Here is an example, looking at each state’s delegation in Congress after the 2018 midterms (limiting it to the Lower 48 for the moment):