The number of crossover districts – 16 in total – is extremely small in historical comparison, but continues a downward trend that reflects the increasing political polarization of our nation. There were 35 crossover seats after the 2016 elections, an increase from 2012 but a sharp decrease from the 83 seats created by the 2008 democratic wave. For much of the post-war period, there were 100 or more such districts, according to the Brookings Institution. To find a lower percentage in a presidential year, one has to go back to the GOP landslide of 1920 when there were only 11 crossovers.
Those districts are now concentrated in just 11 states – as you can see in our “Hexmap,” where all districts are the same size – but Pennsylvania has the unique distinction of being the only state in the nation that is home to both Biden are -Republican “and a” Trump Democrat “seat: the 1st and 8th district.
The first, located in the Philadelphia suburbs, is held by Republican MP Brian Fitzpatrick, an eternal Democratic goal that has always managed to get to the top of the ticket. He did so again in 2020 when his district shifted from a 49:47 lead for Hillary Clinton to a larger 52:47 win for Biden. Nevertheless, Fitzpatrick held back the Democrat Christina Finello with a healthy margin of 56:43.
The 8th, anchored by Scranton / Wilkes-Barre in the northeast of the state also turned bluer, though it still held for Trump: it backed him at 53-44 in 2016, but this time with a much tighter 52-47 spread. demoCritical MP Matt Cartwright outperformed Biden, beating Republican Jim Bognet 52-48.
But Pennsylvania also contributed to the decline in crossover seats as the 17th district in the suburbs of Pittsburgh moved from supporting Trump 49-47 to supporting Biden 51-48. Democratic MP Conor Lamb, who is currently considering running for the Senate, was lucky enough to hold Republican Sean Parnell off in a tight 51-49 race.
At the other end of the state, the heart of Philadelphia gave up the undisputed new holder of the title of “bluest district in America”. That now belongs to Democratic MP Dwight Evans’ 3rd district, a black-majority district that backed Biden by a thunderous margin of 91-8. That leaves California’s 13th district, held by Democratic MP Barbara Lee and favoring Biden 89-9, just barely. It also ousts the 2016 champion, New York’s 15th District, who has fallen to eighth overall with 86-13 biden.
Now that our efforts at the Congress level are complete, we will soon focus on cracking the presidential election results for the country’s 6,764 legislative districts that we expect to keep us busy for some time.
But before we shift gears, we want to recognize a long list of people who selflessly helped us collect hard-to-find data and patiently answer our many arcane questions, people without whom this project would never have been possible. We are especially grateful for that Derek Willis and his team in the priceless OpenElections Project dedicated to the collection and publication of election results, and Benjamin Rosenblatt from Tidal wave strategieswho has worked tirelessly to track down data from every district of New York City.
We are also obliged to:
the incomparable Adam Bonin for all these counties in Pennsylvania, like so many nickels and pennies, he carries in his pocket;
Jeanne Albert, who has graciously molested local officials on our behalf for years;
Gabe Rosenberg for his magic in the office of the Secretary of State for Connecticut;
Our data collection volunteers: Mike Skin, Dovid Holtzman, Neal Traven, Graham Crowe, Jason parsley, and John Ray;;
TC McCarthy and John Tomanelli Newsday to make the impossible possible Nassau County;
Aaron Kleinman at the Future now and his team of data collectors, Kim Beck and Lisa Goldenberg Corn;;
Shiro Kuriwaki for teaching about voting results; and
Jacob Alperin Sheriff, Ben Forstate, Venkat Ranjan, Jayanth Uppaluri, Lisa Needham, Jeff Smith, Arik Wolk and James Newton.
Lastly, we have to thank the sponsor of our “Pres-by-CD” project, Jeff C., who popped up behind the scenes in early 2009 to direct our first attempt to compute this data when we were still known as Swing State Project. Jeff has brought a level of rigor, transparency, and accuracy to the endeavors that lead us to this day and he continues to give us his unique advice.
PS We have one last request to all readers: if you use our data, we would be very grateful if you would quote the daily Kos elections with name and link to us. Thank you!