Image taken from Netivist

Congressional Polarization is Worse Than We Think

James L. T.
Sep 2, 2018 · 4 min read

I recently stated that polarization shouldn’t be measured by the distances between the most liberal Democrat and the most conservative Republican. I also pointed out that ideologically both parties are becoming more tight nit, or homogeneous. It wasn’t until I bore out other trends that I realized how dramatic this was.

There are three major takeaways: First, there is no longer overlap between Republicans and Democrats. Second, Democrats have less ideological spread within their party than Republicans. Third, Republicans are moving to the right more quickly than Democrats are moving to the left.

Using Voteview (NOMINATE data), any number to the left of 0 (negative) represents liberal ideological scores, and anything to the right of 0 (positive) represents conservative ideological scores.

Ideological Spread Within Parties

The above graph shows the standard deviation for all members in the senate based on party for each Senate session between the 80th and 115th. A higher number means that the party saw more diverse ideology within it, and a lower number means that the party saw less diverse ideology within it.

It’s important to point out that while ideologically the liberal camp has become “less diverse”, they have also remained moderated closer to zero for the last eighty years. In other words, the ideological mean of the liberal camp has remained in the same place.

So what do I mean when I refer to “ideological diversity?” I’m meaning that more left or right-wing ideologies are represented within each party as determined by scores farther to the left or right of zero. For example, in the 115th House of Representatives, the ideological spread left of zero only spans to -0.7, whereas the ideological spread right of 0 is from 0.2 to 1.0.

Distance from Closest Party Opposites

The graph above shows the distance between the least conservative Republican (right of zero), and the least liberal Democrat (left of 0). As we can see, that gap has widened 280% since the 80th Congress, and over 360% since the 109th. The difference between the 110th and 115th Senates is that various moderate Republicans retired (or were not re-elected) which is represented more dramatically below. This is the result of moderates within each party retiring or not being re-elected, and more right-wing candidates being elected.

Another question to ask is ff we look at each party as a bubble, what is the distance from the outer edge of that circle from zero?

The graph above shows the distance from zero, which is the ideological middle. From this, we can see that the Republican party held a more consistent outer bound closer to zero than the Democratic Party, but since the 110th Congress this is no longer the case. That distance is driven by two things: fewer moderate Republicans, and the ideological middle of conservatism moving farther to the right (by 50%).

It is important to understand that there were in fact liberal Republicans who were more liberal than moderate Democrats, and there were conservative Democrats that were more more conservative than moderate Republicans. For example, Rep. Brady Gentry (D-TX) was more conservative than 35% of the Republicans in the House during the 85th Congress.

The three graphs above do little justice however to show just how polarized Congress has become. The gif below shows the ideological spread of all members of the House of Representatives between the 80th and 115th Houses.

To summarize the trend being shown in the gif above, you see that the ideological median of the liberal camp (left of zero) holds at -0.3, whereas the ideological mean of the conservative camp (right of zero) shifts from 0.4 all the way to 0.6. Effectively, there is zero overlap between the parties, moderates are nearly extinct, and the conservative wing has become more right wing than moderate.

Where Do We Go From Here?

Pew Research Center

It is worth pointing out that the public is not as polarized as congress, but it is certainly moving farther in that direction. The answer behind the why is pretty simple: the loudest people tend to also be more frequent voters. In effect, polarization within Congress may well be more representative of the polarization between those more ideologically left or right constituents because they actually vote. This should inform us that more political participation in general would help to moderate the polarization within Congress.

How motivate people to care about politics, to participate even in the most basic way such as voting, or to otherwise enter a system that they see as ridiculous or ‘rigged’ at this point is a whole other topic for another day, but one that certainly needs addressing.

James L. T.

Written by

Mental health counselor by day, political blogger by night. #cat person, #liberal. Twitter: @AntiphonSophist

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