https://fusiontables.google.com/embedviz?q=select+col5%3E%3E1+from+1QVyAZxFvArMqkEAVnTeLmAhebS0bwzgiDhn3qdhK&viz=MAP&h=false&lat=37.05628800013914&lng=-93.02554824999993&t=1&z=4&l=col5%3E%3E1&y=2&tmplt=2&hml=KML
The “composite” is calculated as thus.
If the seats were uncontested, 2/3 of the weight is on the 2012 presidential vote, the rest on the 2016 presidential vote; i.e., uncontested seats are treated as if they were open seats. I have also calculated the open seats listed as open in 2018 in Wikipedia in this fashion. The weighing is based on David Shor’s data. https://gist.github.com/davidshor/5ea3e6c4e80cdc87243253e47c47bc41
If they are seats contested in 2016 with an incumbent, 50% of the weight is on the 2016 House vote, 30% is on the 2016 presidential vote, and 20% is on the 2012 presidential vote. This weighing is roughly based on comparing the 2014 and 2016 House elections and taking note of the increased importance of the 2012 presidential vote in the 2017 specials relative to 2016’s House races.
All data is from the Daily Kos.
The rank is the ranking of the districts by partisanship by the composite index.
You can get the source data by clicking “source” in the map legend.
The districts held by the 2017 special election GOP winners are calculated as though their House members in 2016 were still serving today, without regard to the 2017 special election results (as different from the 2016 results as apples are from oranges) as they really cannot be viewed as open seats in 2018.
No attempt is made to account for asymmetric deterioration of incumbent bonuses in bad midterms for a president’s party, as happened in 2006 and 2010 (thus Collin Peterson and other Trump district Dems are probably underrated with this composite).
Other House district maps:
2016 House (two-party):
https://fusiontables.google.com/embedviz?q=select+col5%3E%3E1+from+1Dg51R3pGS5r0HrSuoHSUXR_IxZIfcClrwl7gsLXk&viz=MAP&h=false&lat=37.05628800013914&lng=-93.02554824999993&t=1&z=4&l=col5%3E%3E1&y=2&tmplt=2&hml=KML
2016 presidential vote by congressional district (two-party):
https://fusiontables.google.com/embedviz?q=select+col18+from+1_NolOUGbBkWbAl5TMMZrpba-OazN7DBf7dvSTUie&viz=MAP&h=false&lat=37.05628800013914&lng=-93.02554824999993&t=1&z=4&l=col18&y=2&tmplt=2&hml=GEOCODABLE
2012 presidential vote by congressional district (two-party):
https://fusiontables.google.com/embedviz?q=select+col18+from+1T2Q2YVeHXfCqiV466yZqciXyOF48DMGD3cZ2hxac&viz=MAP&h=false&lat=37.05628800013914&lng=-93.02554824999993&t=1&z=4&l=col18&y=2&tmplt=2&hml=GEOCODABLE
Two-Party Swing between 2012 and 2016 presidential vote:
https://fusiontables.google.com/embedviz?q=select+col18+from+18XmouMM-7G0SD_6dykEyD9gfgNnGmoiPpfbIdMYV&viz=MAP&h=false&lat=37.05628800013914&lng=-93.02554824999993&t=1&z=4&l=col18&y=2&tmplt=2&hml=GEOCODABLE
Two-party House Dem vote performance over two-party HRC vote in 2016:
https://fusiontables.google.com/embedviz?q=select+col18+from+1IdPacdK9LIHkbXRyC2l4WdZx5E6RXCqDmwS70jSK&viz=MAP&h=false&lat=37.05628800013914&lng=-93.02554824999993&t=1&z=4&l=col18&y=2&tmplt=2&hml=GEOCODABLE
Against Jebel al-Lawz 