The Swing Vote on Today’s Supreme Court

 /  Oct. 6, 2019, 5:33 p.m.


When Justice Anthony Kennedy announced his retirement from the Supreme Court last year, analysts scrambled to determine who would replace him as the court’s “swing justice,” the median vote that tips the ideological scales of the nation’s most powerful judicial body. Very quickly, pundits came to a consensus: “There is exactly one potential candidate to fill the swing-vote role Kennedy is now vacating . . . ” announced The Guardian. “Chief Justice John Roberts.”

But with the Supreme Court’s 2018-2019 term finished and the next one beginning this month, that prediction requires a second look. In fact, the entire idea of a single “swing vote” on the bench may have to be thrown out as the court becomes more dynamic—and unpredictable—than before.

The median vote

The most common way scholars measure the ideology of Supreme Court justices is by examining their Martin-Quinn scores, which follow how often justices vote with each other in affirming or reversing lower-court cases. In the Obama era, this pretty clearly mapped out three lanes on the court: Justices Clarence Thomas, Antonin Scalia, Samuel Alito, and Roberts on the right; Justices Sonia Sotomayor, Ruth Bader Ginsburg, Elena Kagan, and Stephen Breyer on the left; and Justice Kennedy in the middle. Replacing Scalia with Justice Neil Gorsuch in 2017 had little effect on this overall composition: Gorsuch, with a Martin-Quinn score only marginally more liberal than his predecessor’s, still landed squarely on the conservative side of the bench.

Typically, justices appointed by the same president agree on most opinions issued by the court; if President Donald Trump had nominated another Gorsuch-style judge, then, Roberts would have found himself alone on the center-right, flanked on either ideological side by four of his colleagues. But Trump’s nominee, future Justice Brett Kavanaugh, proved to be anything but Gorsuch’s mini-me; the two justices have voted differently from each other in their first joint term more than any other pair appointed by the same president in more than fifty years. In fact, Kavanaugh voted with his fellow Trump appointee the same amount as with the two moderate liberal justices, Breyer and Kagan.

Because of this, looking at the 2018-19 term, Roberts is not the “monkey in the middle” that pundits expected him to be. That position belongs to Kavanaugh, whose Martin-Quinn score is ever so slightly more liberal than Roberts’, making him the court’s ideological center vote.

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But while Kavanaugh may be the median vote, he doesn’t look to be a solitary swing vote like Kennedy was. For one, while Kennedy was isolated in the middle, Kavanaugh and Roberts are closely ideologically aligned. The two agreed with each other on 92 percent of cases last term, just barely losing the “best friends on the court” award to Ginsburg and Sotomayor by less than one percent. As one might expect from ideologically central justices, they were also the two in the majority most often, Kavanaugh agreeing with the court 88 percent of the time and Roberts 85 percent.

Shifting coalitions

Even describing Roberts and Kavanaugh as the two swing votes, however, would be misleading. Looking at all the years since 2005, when Roberts became chief justice, the court during the 2018-19 term appeared much less cohesive across the board than any other. The number of unanimous decisions was unusually low, and the number of 5-4 decisions was close to an all-time high, with 29 percent of cases being decided by just one vote. Contrary to expectations, the conservative bloc did not dominate these split cases; of all cases with the four liberals on one side and at least four conservatives on the other, the liberals prevailed 59 percent of the time by persuading a conservative vote to their side, compared to 41 percent of ideological 5-4 cases when the five Republican-appointed justices voted together. However, unlike what the justices’ Martin-Quinn scores may predict, the conservative justice most likely to cross the aisle was neither Kavanaugh nor Roberts—it was Gorsuch.

Part of the reason behind this oddity is that Martin-Quinn scores measure ideology based solely on one dimension, while in reality the motivations behind Supreme Court rulings are much more nuanced. For example, while Gorsuch is a strong ideological conservative in most cases, he appears much more liberal in criminal law cases, as well as those dealing with tribal law. This makes the liberal/conservative dichotomy less useful for a judge like Gorsuch, who agrees most often with the ultra-conservative Thomas but is also the conservative most likely to vote with the liberals. Other scholars have further criticized the Martin-Quinn methodology for its assumption that each case presents a decision between a liberal outcome and a conservative one, when a host of other factors, such as precedent, are at play.

Whether Kavanaugh remains in the middle or moves towards a pole, the power of the “swing vote,” which for years rested on Kennedy’s shoulders (and, before him, on Sandra Day O’Connor’s), appears to have been diluted. For the first time on the Roberts Court, this past term each conservative aligned themselves with the liberals to form a 5-4 majority at least once, and the total number of different one-vote majority coalitions last term reached an all-time high.  

What mattered

Last term, there were only a few newsworthy cases that allowed the opportunity for one justice to stand out as the deciding vote. The most sensational was a challenge to the president’s contentious addition of a citizenship question to the 2020 Census, which research suggested likely would have led to inaccuracies in the Census. This case, Department of Commerce v. New York, was one where Roberts played the pivotal swing justice role predicted for him, when he chose last-minute to join the liberals in declaring the government’s stated reason for adding the question insufficient. This was a relatively rare anti-Trump move for the chief justice, who has sided with the president allowing a ban on transgender people serving in the military, upholding the travel ban, and letting Trump use military funds for his wall on the southern border.

Another controversial case to confront the Supreme Court last term was Rucho v. Common Cause, which challenged gerrymandered districts in North Carolina and Maryland. Some of the congressional districts of North Carolina created after the 2010 census had been previously struck down by the Supreme Court for excessive racial discrimination. The districts drawn to replace them, however, were just as bad; while Republicans and Democrats vote in the state in roughly equal numbers, ten of the thirteen districts favored Republicans. In fact, using the legal guidelines for drawing district lines, it was statistically impossible to create a more gerrymandered map than the one drawn by the legislature. Over the protests of the liberal justices, the Supreme Court’s five conservatives stuck together and decided that “partisan gerrymandering claims present political questions beyond the reach of the federal courts.”

Though last term did have its fair share of partisanship, that is not to say that all controversial issues—which are often viewed as partisan—will fall along ideological lines. For example, Rucho wasn’t the only gerrymandering case to face the court. In Virginia House of Delegates v. Bethune-Hill, the Virginia House of Delegates claimed that they were “injured” by being forced to implement a court-drawn map that replaced one that Republicans had unconstitutionally racially gerrymandered. The decision that redistricting “inflict[s] no cognizable injury on the House” came down to a 5-4 split, but it was far from ideological: The three most liberal members of the court, Sotomayor, Ginsburg, and Kagan, were joined in the majority by two of the more conservative justices, Thomas and Gorsuch. The four dissenters, Breyer, Kavanaugh, Roberts, and Alito, largely make up the ideological center, disagreeing with the justices to their left and right.

In Gundy v. United States, the sole deciding vote came not from a judge close to the ideological center, but rather from one of the court’s staunchest conservatives. Gundy concerned to what extent one branch of the government can delegate its authority to another—in practice, how much lawmaking power Congress give to the federal bureaucracy. Congress has been ceding its authority for decades to the executive branch, letting, for example, the EPA set environmental policy with the force of law. Had the conservatives stuck together, they could have thrown out up to 300,000 regulations—which is in line with conservative rhetoric regarding deregulation—about everything from the SEC to the Consumer Product Safety Commission. Stopping that was the solidly conservative Alito, who sided with the liberals to preserve the current state of the bureaucracy (although he left the possibility of changing his mind open in the future).

We’ve seen in this term a fair amount of uncertainty regarding the future of the role of a swing justice. Next term is slated to be even more contentious, allowing the opportunity for a swing justice to emerge more fully—or not. The court will have to decide whether the Civil Rights Act protects against discrimination based on sexual orientation (Altitude Express Inc. v. Zarda) and gender identity (R.G. & G.R. Harris Funeral Homes Inc. v. Equal Employment Opportunity Commission), whether former president Barack Obama’s DACA immigration program is constitutional (Regents of the University of California v. United States Department of Homeland Security), and whether a now-amended New York City gun law that banned the transportation of a locked and unloaded handgun outside city limits violates the Second Amendment (New York State Rifle & Pistol Association, Inc. v. City of New York). Most controversially of all, they will review a Louisiana law limiting access to abortion, the first abortion-related case of the Kavanaugh era, which some pundits have argued could provide conservative activists the opportunity to dismantle Roe v. Wade. Whether the court’s currently nebulous coalitions will solidify into a five-person conservative bloc dominating the four liberal justices; whether there will be a consistent swing justice; or whether the Supreme Court becomes less partisan remains to be seen. The answer to these questions may well decide the fate of many topics central to the modern political arena for years to come.

How much does 2020 matter?

Even if the Democrats defeat the president in the 2020 election, they are unlikely to be able to push the court significantly to the left, since they will probably only have the chance to replace their own. Given the ages and genders of the liberal justices, it is nearly twice as likely that a Democratic president would only be able to stem the loss of liberal justices rather than move the court to the left by replacing a conservative.

And that’s Democrats’ best-case scenario; in the not-unlikely case that Trump wins reelection, he will probably have the opportunity to replace a liberal justice. It’s even entirely within the realm of possibility (about as likely as rolling a “1” on a six-sided die) that before Democrats get another chance at the White House in 2024, conservatives could secure a 7-2 supermajority on the court—one that, given the conservative jurists’ relative youth, could easily last twenty years or more.

Looking forward

When considering Kavanaugh’s middle-of-the-road record last term, experts warn a new justice’s first term is rarely representative of how they will act in the long run and that pundits should be careful forecasting how he will act in the future based on his first term. “We tend to see that first-term justices dissent less frequently, and they definitely tend to write dissents less frequently,” Dr. Adam Feldman, an expert on the judicial branch and creator of the blog Empirical SCOTUS, explained to The Gate. “There's this notion of camaraderie, and also of finding one's place on the court, that we see early on.” Later in their tenure, he added, justices “come into their own and find their own Supreme Court jurisprudence as they spend some more time there.”

No matter what, Kavanaugh, Roberts, and Gorsuch will be key players in American politics for decades to come. On the one hand, if they coalesce into a single voting bloc aligned with Alito and Thomas, the court could become a staunch ally to conservatives in upholding gun legislation, corporate money in politics, and restrictions on abortion. On the other hand, if some recent trends continue —with justices defying the standard liberal/conservative dichotomy increasingly often—then the idea of a “swing justice” may become obsolete, leading to a less predictable court than before. 

The image featured in the headline of the article is licensed under the Creative Commons. The license can be found here and the original photo can be found here. No changes were made to the photo, and the photographer is WEBN-TV. The first graphic in the article was created by the author, and the second was created Adam Feldman, who was interviewed by the author. The original can be found here

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Jake Biderman

Jake Biderman is a fourth-year political science major interested in law, journalism, and governance. He has worked for outlets including the Des Moines Register and Fox News, covering the Democratic primaries and a Democratic presidential debate. When he’s not worrying about Americans’ critical thinking skills, he’s exercising, learning foreign languages, or watching baseball. Go Nats!


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