In early 2001, in the wake of the closely contested 2000 presidential election, I wrote an Introduction to The Almanac of American Politics called “The 49 percent nation.” Not only was the popular vote for president 49% to 49%, but in each of the three preceding congressional elections, both parties had received either 48% or 49%, and Bill Clinton had won the preceding presidential election with 49%. We were pretty evenly divided.

As we are these days. In 2016, President Trump won his majority in the Electoral College by winning Pennsylvania, Michigan, and Wisconsin by a total of 77,000 votes out of 137 million cast. Joe Biden won his majority in the Electoral College by — and this is an approximation, subject to change and probably upward adjustment in the final count — by winning Georgia, Arizona, and Wisconsin (there it is again) by a total of 49,000 votes. Those narrow margins gave each of them their 306 electoral votes in their respective victories.