Fun Facts About Adjacent Congressional Districts

Mike Bostock of the New York Times has created an interactive map that allows one to visualize all the Congressional Districts adjacent to the one selected. We decided to dig into the data behind this map to see what interesting nuggets of information there might be.   Those are presented below.   The next time any of our readers appears on Jeopardy, and the category Adjacent Congressional Districts is used, he or she will be well prepared...

• Four Congressional Districts in the Continental US are adjacent to every other District in their state, but none outside the state.   These are:  AR-02, CT-03, NM-01 and OR-05. Considering all 50 states, both Hawaii Districts qualify as well.

• An additional 190 Districts are adjacent to one or more, but not all Districts in their state and none outside the state.
• No Districts, excluding the seven states with one At-Large District, are only adjacent to districts outside their state.   (Alaska's District is not adjacent to any others).
• The remaining 232 Districts are adjacent to Districts both inside and outside their state.

Districts adjacent to the fewest Districts:

• In the continental US, the only District adjacent to a single other District is NY-26.   This District, which includes Buffalo, is surrounded by NY-27 and Canada.

• 18 Districts are linked to two others:  FL-13, FL-16, FL-19, FL-21, FL-26, LA-02, ME-01, NE-02, NM-01, NV-01, NY-20, NY-25, OH-03, PA-14, SC-01, TX-16, TX-34 and UT-04.
  • Of these, all are linked to two districts in the same state except for ME-01, NE-02 and TX-16, which are each linked to one in-state and one in an adjacent state.

Districts adjacent to the most Districts and states:

• Four Districts are adjacent to 11 others:
  • AZ-04:          Five Districts in AZ, three in CA, two in NV and one in UT.
  • CA-04:          Ten in CA and one in NV.  (Note that CA-08, with the green dot, is adjacent to both AZ-04 and CA-04).
  • MO-06:         Three in MO , two in IA, two in IL, two in KS and two in NE.
  • OH-06:         Five in OH, three in WV, two in PA and one in KY.
  • Eight districts are adjacent to ten others:   AZ-01, CA-08, CO-04, FL-17, IL-16, KY-04, MD-01 and TX-04.
  • NE-03 is the only District adjacent to Districts in seven states (CO, IA, KS, MO, NE, SD and WY).
  • CO-04, SD-AL and WY-AL are adjacent to those in six states.

 Love thy Neighbor?

• 23 Democratic seats are surrounded by only Republican-held Districts, led by AL-7 with seven.
• Only two Republicans are surrounded by all Democrats, both in New York.   NY-11 has eight adjacent Democrats, while NY-02 has three.
• 45 Democrats are surrounded by blue, led by MA-02 with nine.
• 48 Republicans are surrounded by red, led by TX-04 with ten.