This article was co-authored with the brilliant and talented Harro Cyranka, DKC Analytics lead data strategist, formerly of Lincoln Park Strategies and the AFL-CIO, lover of apple juice in the morning, and great promoter of German precision.

Facebook has taken a lot of criticism for enabling fake news and maybe even Trump’s victory. Underlying the Trump strategy is one dataset of increasing importance in politics: how social media users sort themselves in the political spectrum. We hope you’ll enjoy this glimpse into the ideological affiliations of Facebook users across America’s Congressional districts.
A Note on Methodology
We wrote a script in R that went through each congressional district and retrieved the counts of adult Facebook users classified into one of the five ideological buckets: very liberal, liberal, moderate, conservative, and very conservative. We bundled liberals and very liberals into a liberal camp, while conservatives and very conservatives were bundled into a conservative camp.
While differences might exist from district to district, around 90% of all Facebook users in the United States have been assigned an ideological label. Therefore, the proportions are based on the total number of people with ideological labels instead of the whole district population.

The 6 Types of Congressional Districts, According to Facebook Ideology

We divided each congressional district into six categories based on the group that holds the plurality or majority in each district (Majority Liberal, Plurality Liberal, No Edge, Plurality Moderates, Plurality Conservative, Majority Conservative). The following table displays the distribution:

As the table indicates, liberals hold an edge on Facebook: 53% of all congressional districts lean to the left. However, 44% of congressional districts lean conservative. Just ten districts (2%) have a plurality of moderates, whereas two districts have the same number of conservatives and liberals: FL-04 and GA-07.
This polarization more-or-less mirrors the national electoral map, as conservatives tend to dominate the Midwest, the South, Mountain West, while liberals are stronger in the Northeast, California, and in the large urban areas throughout the country (Alaska and Hawaii not shown).

Scoring the Districts

The color-coded map alone doesn’t tell us a lot about the gap between liberals and conservatives in any given district, so we developed a score. Using the log of the proportions of liberals and conservatives in each district, we assigned a real number to each district. Liberal districts received positive scores, while conservative districts ended up with negative numbers (a score of 0 indicates that the liberals and conservatives have the same number of users in that district). Moderates were excluded.
The following histogram shows the distribution of scores and it also traces the medians for the following group of districts:
1 — Median score for all districts (black line)
2 — Median for plurality and majority conservative districts (red line)
3 — Median for plurality and majority liberal districts (blue line)
4 — Median for the ten districts where moderates constitute the plurality (green line)

As the histogram suggests, liberal districts tend to be further away from the center than conservative districts. Even where conservatives have the upper hand, liberals still comprise a significant portion of Facebook users.

The 10 Most Liberal Districts on Facebook

Of the top ten most liberal districts in the country, eight are in New York State, one is in California (CA — 13) and one is in New Jersey (NJ-10). The following map zooms in in the congressional districts surrounding New York City, highlighting those extremely liberal congressional districts. As the map shows, these districts are in the outer boroughs. The congressional district in New Jersey encompasses the city of Newark, while CA-13 is in the San Francisco Bay Area.

The 10 Most Conservative Districts on Facebook

On the other hand, seven different states house the top ten most conservative districts. Missouri and Tennessee are the only two states with more than one.

Facebook Could Flip 65 Districts!

The next step in our analysis was finding where there is a “mismatch” between ideology and political representation — highlighting liberal districts represented by Republicans and vice-versa.

12 Top GOP Targets

Currently, there are twelve congressional districts where conservatives outnumber liberals although their representative is a Democrat. The Midwest is home to seven of these districts. Another three conservative districts represented by Democrats are in the South, with one being in the swing state of Florida. The remaining two are in Arizona and Oregon, respectively.

53 Top Democratic Targets

The mismatch between ideology and representation is much more pronounced for left-leaning districts. Republicans represent 53 districts where a majority or a plurality of Facebook users are left-leaners. Twelve of these districts are in California alone, including the Congressional seat held by Majority Leader Kevin McCarthy. There are another 15 left-leaning districts with a Republican representative in the Northeast, equally distributed between New Jersey, New York, and Pennsylvania.

Republican Representatives Rule the Moderate Districts

Republicans represent seven districts with a plurality of moderate Facebook users, including four in upstate New York and Maine’s 2nd congressional district. Democrats represent the two moderate-plurality congressional districts in New Hampshire and Ohio. These GOP reps could be in danger if Trump’s low approval ratings persist.

Conclusion

It’s hard to dispute the facts of the modern media environment: social media shapes political news, the internet drives campaign strategy, and traditional advertising and organizing tactics are less effective by the day. The data doesn’t lie: both parties have their work cut out for them