Last week, I wrote up a post describing how the parties in Congress have polarized in part because they represent more ideologically distinct districts and states than they used to. I produced a chart showing how the states themselves are polarizing; to the extent senators are simply representing their states today, that would lead to much more partisan behavior than it would have a few decades ago. Here's the same sort of chart showing the presidential vote by congressional district. It's a similar story. The red columns show the number of congressional districts in the 1968 presidential ... Read More