Ideological Scores Over Time

From 1994 to 2015, Pew Research Center conducted surveys to score respondents on a 10-point ideological scale and measure opinions about controversial issues. Their results showed that in the past decade, members of both parties became more ideologically consistent, with fewer Americans occupying an ideological “middle ground.”


On the left, each colored square represents the percentage of respondents with an ideological score of 0-10 points left or right of center. Lines show how median values have changed over time. The charts on the right show the distribution of scores, inspired by the charts from Pew Research Center.


The overlapping areas show that some people who identify with a party od not align with that party’s ideology. In the 1999 survey, 0.7% of Republicans were “consistently liberal”, 8 points left of center. Conversely, 0.2% of Democrats were “consistently conservative”, 8 points right of center.


Among politically engaged respondents, the partisan gap was steady at 5 points despite the overall medians shifting leftward. Sometime during the Bush years, the gap widened as Democrats kept the status quo and Republicans moved back to their 1994 ideological median. In recent years, the gap has widened to 11 points as both parties became more ideologically consistent.


This general trend is true for the general population as well, although the gap is not as extreme as the politically engaged group. Choose a segment at the top right to see the difference.



Quantifying Ideology

As we review how ideology has changed over time, we need to understand how these scores are developed. Answering the same questions given by Pew will give you a sense for how the scores are calculated while showing you where you fit on the left/right scale. Each set of statements is meant to identify you with either a conservative or liberal view of our society. While this scale may not be a perfect measure, the survey’s consistency makes it useful to compare shifts over time.


For each row, move the slider toward the statement that matches your opinion. As you choose each one, notice how the dot moves along the bottom. Every answer agreeing with one side moves you closer to that side of the ideological scale. If you do not agree with either statement, it’s okay to leave the slider in the middle. Many survey respondents abstain from one or more answers, which is the only way to have an odd number as the overall score.


When you have answered all the questions, go back and see how your answers match those of the survey participants. The bubbles on each side give you the percentage of people who agreed with each statement in 2014 (the most recent year in which Pew offers full survey details).



Key Issues

Pew also asked people their opinion on controversial topics like: health care, abortion, guns, surveillance, immigration, and social security.  With this chart, we can easily see how the split among ideological segments on certain issues, while there is general agreement on topics like social security.


We see a different split when breaking it down by other segments like age, religion, race, or income. Use the selection at the top right to change the view. Hover over a colored bar to see the response statements and what percentage of people agreed with that selection.



Was He Right?

This leaves us with more questions: what do we do about it? What caused it? The data here may give us some clues, but further investigation would be necessary.


Way back in 1780, John Adams wrote to Jonathan Jackson, saying:


“There is nothing I dread So much, as a Division of the Republic into two great Parties, each arranged under its Leader, and concerting Measures in opposition to each other. This, in my humble Apprehension is to be dreaded as the greatest political Evil, under our Constitution.”


Does his perspective on political parties explain our current situation? I leave it to the discerning data analyst and student of political history to investigate the answer.