ggplot2 is not only the R language’s most ... t affect the “main” part of your dataviz—that is, the bar/point/line sizes, colors, orders, and so on. Instead, it’s all about customizing ...

including sizing points by total county population and coloring them by region. geom_smooth() adds a linear regression line, and I also tweak a couple of ggplot design defaults. The graph is ...