The Washington PostDemocracy Dies in Darkness

The Supreme Court hasn’t followed public opinion for 50 years. Why would it start now?

President Trump’s Supreme Court nominee Judge Brett M. Kavanaugh testifies before the Senate Judiciary Committee on Sept. 6. (Alex Brandon/AP)

Justice Brett M. Kavanaugh’s confirmation reawakened concerns about the representativeness of the Supreme Court. As Brendan Nyhan pointed out here at TMC, Kavanaugh was appointed by a president who lost the popular vote and confirmed by a Senate majority that represents less than half of the U.S. population. Scholars have raised concerns that the court will now be far more conservative than the country as a whole.

If that proves true, it won’t represent anything new. In our research, we argue that any overall correspondence between public opinion and Supreme Court rulings depends on a single historical period: the “Warren Court,” when Earl Warren served as chief justice. Once you set aside that period, court decisions do not follow the general tenor of public opinion.

Of course, many studies have examined the relationship between public opinion and Supreme Court decisions. Most studies have found some relationship, although the finding is not universal. However, studies do not agree on whether the impact of public opinion is large or small, or limited to important cases or unimportant cases or cases on either extreme but not in the middle.

We argue that understanding how public opinion may affect court decisions depends crucially on the Warren Court era (1953-1969). The Warren Court was historically liberal at a time when overall public opinion was also trending liberal. As a result, court decisions and public opinion were pretty strongly correlated during these years.

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Here’s how we did our research

But if you set aside the Warren Court era, the picture changes. To show this, we drew on a measure of public opinion created by political scientist James Stimson. This measure combines survey questions about a wide range of topics into a single measure of the relative liberalism or conservatism of the American public. Higher values on this measure indicate a relatively more liberal public. Obviously, public opinion is more complex than this single measure, but it nicely captures the overall ideological “mood” of the country.

We then measured the overall ideological direction of Supreme Court decisions based on data from the Supreme Court Database, which codes each decision as liberal or conservative. This measure is just the percentage of cases decided in a more liberal direction.

The figure below shows how these two measures compare for the period from 1953 to 2017. If there is an association, then court decisions should be more liberal when the public is more liberal.

Overall, there is a relationship, as the dashed line shows: The more liberal the public, the more liberal were Supreme Court decisions. The Warren Court years — noted with asterisks — are one example. It was a liberal court in a liberal era for public opinion.

However, once the Warren Court years are removed, there is no relationship. The solid line is almost perfectly flat.

Why does the Warren Court appear more responsive to public opinion? One possibility is that Warren himself was a politician. As the former governor of California, he may have been more skilled both at reading the public mood and at getting other elites to follow his lead. In fact, the paucity of politicians on the court — Sandra Day O’Connor was the last one — may help explain why the court does not clearly mirror the public’s ideological mood.

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To be sure, the court’s decisions on specific issues — such as same-sex marriage — may track public opinion, at least to some extent. And there is always the deeper question of whether we really want the court to follow public opinion. At times, the court may need to ignore majority opinion so that it can affirm the constitutional rights of unpopular minorities. At the same time, a court that is less responsive to majority opinion may sacrifice some of its legitimacy.

There is no simple answer, and there can be problems with both scenarios. Regardless, it’s important to know which problem we’re facing. Our results suggest that there has been no relationship between overall public opinion and the court’s decisions for the past 50 years. If critics are right and Kavanaugh’s arrival helps produce court decisions that diverge from what the majority of the public want, this will only continue a decades-long pattern.

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Ben Johnson is an assistant professor of law at Pennsylvania State University Dickinson School of Law (University Park).

Logan Strother is assistant professor of political science at Purdue University.