A Breathtaking Illustration Of How Congress Got So Partisan

The data viz designer Mike Cisneros has mapped out the political positions of every member of Congress ever, starting with the first Congress in 1789 up until the 115th Congress that’s currently filling the news cycle with so much anguish. The central visualization is a giant scatterplot, where positions are mapped based on how conservative or liberal each Congress member is economically and socially. The data, analyzed by UCLA’s Department of Political Science and Social Science Computing, measures every historical Congress member’s political beliefs based on their voting record, with the two central factors being economic forces and social issues. The average for today’s Congress is more economically conservative and–surprisingly–slightly socially liberal.

Fascinatingly, below the galaxy-like map, Cisneros also visualizes the formation of our modern-day political sphere over the past 228 years. Initially, Congress is fragmented in a group of morphing political parties–Federalists, Whigs, Democrats, Republicans, Democrat-Republicans, Andrew Jackson’s party, the anti-Andrew Jackson party. “By the 25th Congress, in 1837, U.S. politics have settled into a primarily two-party system of Whigs and Democrats,” Cisneros tells Co.Design in an email. “This is where an ideological gulf between the two main parties begins to become evident.”

As the decades progress, the divide between the two parties gets deeper and deeper, angling more conservative overall in some years and more liberal in others. In the 1920s, parties are mostly divided by how they approach economic issues, while both Republicans and Democrats run the gamut on social and race-related issues.

A striking shift occurs beginning in the Bush era, and it’s magnified during the Obama years. The clusters of red and blue dots, while once much more distributed in stretched-out, mirrored cloud shapes, begin to separate further and coalesce into compact groups that look more like tightly packed balls.

The viz points to how the parties have become more entrenched in their belief systems, with the breath of the spectrum along which Congress members’ positions lie decreasing over time on both sides of the aisle. It’s “almost like a cell dividing into two,” Cisneros writes. “Is it any wonder that there is a historically small amount of bipartisan governance?”