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A Short Stroll with Historical Presidential Approval Ratings

Much has been made in the news lately about Trump’s approval rating, especially with the recent spike in his approval (largely due to a rally-around-the-flag effect) and the 2020 election fast approaching (is it really May already?). To the politically observant, it may even seem the topic has come up even more than its usual over-saturated frequency. With our obsession over Presidential approval ratings, what can we learn from looking at past Presidents’ ratings? In this post, I’d like to cover a somewhat more lighthearted subject than my last topic and explore the data on historical President job approval ratings.

As Gallup puts it, “Presidential job approval is a simple, yet powerful, measure of the public's view of the U.S. president's job performance at a particular point in time.” Of course, it's only one, very limited dimension of assessing the success or even popularity of a President. While much can be gleaned from tracking the movements in this measure, certainly much more context and data is required before drawing any bold conclusions. That being said, approval ratings offer a useful headline summary of how the public contemporaneously perceives the President. In a way, the current approval rating for a president can have a powerful impact on influencing real decisions by the President, their administration, and the political parties.

Speaking of Gallup - one of the most well-respected and well-known pollsters - they first began reporting on PJAR in 1938: the midst of FDR’s permanently record-setting 4 terms in office. Amazingly, for almost its entire run from pre-WW2 to today, the polling and measurement method has remained largely the same. This is excellent news for any time series analysis - we can better justify comparing observations over long periods of time and attributing trends to potential explanatory factors. Often in long-running surveys, the survey methodology tends to change: from the wording of certain questions to the method of data compilation, even the subtlest shifts in how the data is generated can result in significant complications for time series analysis. By using the available Gallup data, we can trust that the data is (relatively) consistent and therefore usable for historical comparisons.

The President’s Job Approval rating (PJAR) really came into the public spotlight starting with Truman, which is when things got interesting. During the Korean War, Truman’s approval rating rapidly dropped dramatically, which was the first such occurrence in the modern era for a president. It was especially unusual since Americans had a high propensity to support the president regardless of political affiliation at this time. As political polarization has resurfaced and surveys and political polls exploded, data on approval ratings have become more prominent, especially in the news. For this reason, and even more so because the data is not as available nor as reliable pre-1940s, I’ll be focusing on the PJAR from Truman onwards in this post. 

Note: I’ll only be using the approval rating in this post - not disapproval or net approval. That leaves out some important information, such as the number of undecided/”don’t know” respondents, but for purposes of brevity I’ll only be looking at this one measure.

First Look at the Data

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The first step in any decent analysis is to simply plot the raw data. There’s a lot going on here, but from just the raw data alone we can form a number of initial impressions. We see some huge spikes in the data - around 9/11 for W. Bush and the Gulf War for H.W. Bush - as well as some real low points - Nixon after Watergate and Truman as the Korean War dragged on (see chart below). We can start to distinguish between which Presidents’ had more relatively volatile ratings (again, the Bushes), relatively stable ratings (Eisenhower), and who became more or less liked over time. We also notice that for the most part, approval ratings seem to remain within the 40% to 60% range - only Eisenhower and JFK managed to stay above the 60% mark for most of their presidency. Besides that, it’s hard to really tell what’s going on. It’s still too early to generate any conclusions, and the eye test should only be used for general comparisons. Let’s clean things up a bit.

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One quick way to clean our chart without significantly transforming the data is to apply a smoothing function to our time series. “Smoothing” is a simple method for making charts more readable (see: prettier) without greatly manipulating the data from its original form. It retains the general trends in each approval rating while minimizing the ‘noise’ - high-frequency movements in the data. One well-known phenomenon with Presidents now becomes clear after smoothing - the “honeymoon period” that often occurs upon assumption of the White House. For many Presidents, such as Truman, LBJ, Ford, and Carter, their highest ratings occurred at the very start of their terms.

High Highs, Low Lows

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An excellent way to visualize the distribution of several categories (categories here being Presidents) of data is the boxplot. The median PJAR for each President is represented by the bold line within each box, while the top and bottom of the boxes themselves represent the first and third quartiles. The lines outside the boxes are derived from a slightly more complicated method, but basically capture the majority of the underlying distribution. First, note that the overall average for the approval rating of our entire presidential sample is 49.5%, with most observations falling into the 40-60% approval range. Truman has had the lowest average approval rating through his time in office, falling below the 40% mark. Both Trump (so far) and Truman are the only Presidents to average under 45% for their approval rating in the Gallup poll. On the sunnier side of things, JFK has enjoyed the highest average approval rating - just over 70%! However, his approval rating was falling over time and an argument could justifiably be made that had he spent more time in office he would’ve finished with an average more in line with the other Presidents in our sample. The next most popular after JFK is Eisenhower, impressively clocking in at about 64% approval over his full eight years as Chief. 

As can also be gleaned from our boxplots, both Obama and Trump’s approval ratings remained for the most part within a remarkably narrow band of about 5% (with Obama having a cluster of outlier data points represented by the dots). Contrast this with W. Bush, whose bottom and top quartiles are separated by over 20% - the widest spread among all Presidents! What’s to explain for this recent diminishing of approval rating variance? Theories range from increasing political polarization to the Presidents’ personalities - but there’s no solid answer. 

Red vs. Blue

Another relevant dimension to divide the data is by political party affiliation of Presidents. Grouping our Presidents by their party label and averaging their approval ratings by days into office, we can compare the average PJAR of a Republican versus a Democrat over time.

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The shaded gray areas represent confidence intervals. An interesting pattern emerges here, where Democrats seem to be more popular at the beginning and end of their terms, while Republicans follow almost a mirror of that pattern and tend to peak sometime in their first term, then steadily drop. We see the honeymoon effect in action again, though much stronger for Democrats initially. Either way, neither party on average seems to repeat the peaks in approval reached during their first 1,000 days in office. Perhaps there’s some hidden political wisdom to FDR’s first 100 days strategy. In the end, this chart should be taken with a very large grain of salt - sample size here is small, as we are averaging over only 6 Democrats and 7 Republicans. Sample size in the second half of the chart is even smaller since not all Presidents held office for the full 2,920 days represented by two terms. Looking at only the PJAR also restricts any conclusions we may wish to make. Certainly other factors, among them economic conditions and wars, played outsized roles in determining the approval rating of a President, regardless of the party affiliation.

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Another angle to compare the average performance by political party is to return to the beloved boxplots. This time the results are less visually impressive, although perhaps the very fact that the chart appears boring is itself an interesting result! Democrats just barely squeak out a higher average approval rating, and also seem to have slightly less variance than Republicans. So despite significant differences in the distribution of approval ratings over time between the parties (as seen in the above chart), the end result is numerically similar: about 50% average approval and a tendency to stick in the 40-60% range. Of course, removing the time dimension as we do here is removing a very important, very relevant factor.

Concluding Thoughts

Even though we stuck to just one measure of a President’s popularity - the job approval rating as surveyed by Gallup - we were still able to come away with several initial findings. Most Presidents tend to start at an above-average approval rating, a phenomenon known as the honeymoon period. Individually, all Presidents since Truman have gone through a fair amount of “popularity turbulence” during their time in office, ranging from the high 60 %s to the low 40%’s. Wars and recessions, in particular, can hike or drop approval by double-digits in a matter of weeks. However, in recent times the PJAR has stabilized. Whether this narrowed range in approval is a fad or paradigm shift is yet to be seen, and far beyond the scope of this article, which was only meant to be a casual discussion of the PJAR over time.

Final Comments

Astute readers may have noticed that Obama’s PJAR line is somewhat noisier (visualized in the charts, the line appears thicker than the other Presidents’) - the measurement method was changed for his term which resulted in a different frequency of observations - but overall comparability is the same.

Special thank you to Gerhard Peters at UCSD for making the Gallup Poll data publicly available and easily accessible at https://www.presidency.ucsb.edu/statistics/data/presidential-job-approval.

Charts and maps seen in this post were created in R, using the ggplot2 and RColorBrewer packages.

If you have questions or constructive feedback, feel free to email me at troded24@gmail.com, submit an inquiry on this website, or leave a comment on this post! Thanks for reading.