Republican House Members Have Polarized More Than Their Democratic Counterparts

[Saviolo]

From The Crosstab: http://www.thecrosstab.com/2017/07/22/congress-polarization/

When last we chatted, I talked of how congressional elections have shifted to reflect national politics more than local influences. Importantly, I noted that this may be less the result of ideological “polarization” — the process by which the beliefs of partisans move left/right — and more the result of partisan “sorting.”

But polarization does exist, and it is real. This is especially true of elites in government: congresspeople in particular.

Ian McDonald, a visiting professor at Lewis & Clark College in Portland, Oregon had the incredible idea to graph the distribution of House members’ ideology over time. Using the distribution of a mathematical representation of ideology called DW-NOMINATE, McDonald showed how Republicans have moved right on mostly-economic policies over time, while Democrats have generally stayed ideologically the same.

I have added to his graphic (which appears on the left below) with a second mathematical representation of ideology in DW-NOMINATE – a so-called second “dimension” – to show how Democrats have changed in ways McDonald’s graphic does not show. This second dimension is often referred to as a “social” dimension, mainly encompassing the shift in views towards race that started to flip the parties in the last 1960s.

And an interesting tweet on the subject (that led me to the article):

Link to tweet