Iowa, Minnesota, and the Anomalous Zone on the U.S. Electoral Map

In recent U.S. presidential elections, rural counties have tended to vote heavily for the Republican candidates. As a result, most of the United States is shaded red on county-level electoral maps. Most of the low-population counties that do support Democratic candidates fall into one of several categories. In some cases the explanation is clearly demographic; the heavily African-American belt stretching …