Predicting the Supreme Court's Next Moves: Fourth Amendment Edition

By Matthew Tokson

Now that American politics has returned to something resembling normalcy, it's a good time to consider the future of the Supreme Court in the Biden era. Eric Segall recently previewed the direction that the Court is likely to take over the next several years. As he convincingly argues, on issues like abortion, regulation of business, civil rights, affirmative action, voting rights, and many others, the Court's rulings will likely shift from conservative to very conservative. On a theoretical note, I'd add that increasing polarization and the expanding politicization of policy issues will likely shrink the sphere of legal issues where party affiliation is irrelevant. To be sure, the recent resolution of cases like Trump v. New York suggests that the Court may exhibit meaningful restraint in adopting radical changes to existing laws or constitutional practices. But generally, the Court's strong rightward tilt will drive outcomes in most of the ever-growing proportion of cases with a strong political valence.

In the Fourth Amendment context, however, there is less polarization--and substantial ambiguity. Justices Barrett and Kavanaugh are a particular enigma here, as they've decided few or no Fourth Amendment cases since joining the Court. And Fourth Amendment search law was undergoing dramatic changes even before the Court's composition changed. In this post, I'll describe some mysteries about the future direction of Fourth Amendment law and make some evidence-based predictions about the new Justices' approaches to future cases. 

In 2018, the Supreme Court handed down a remarkably important opinion in Carpenter v. United States, which established that digital information disclosed to a third party may still be protected by the Fourth Amendment. Because most digital information in the modern world is exposed to third-party service providers, this was a potentially momentous development in Fourth Amendment law. Carpenter was a 5-4, however, and going forward it's unclear whether the Court will continue to protect digital information in the internet age.

In the late 1960s, the Supreme Court established that an act of surveillance that violates a person's "reasonable expectation of privacy" is a Fourth Amendment search, generally requiring a warrant. This test originated in Justice Harlan's concurrence in Katz v. United StatesAnother mystery is how many Justices will continue to apply the Katz test, and how many will eschew Katz for a more property-based test. And for those that do adopt some kind of property theory of the Fourth Amendment, which will adopt an expansive theory and which a narrow one? 

Here's how I see this playing out.

There appear to be five Justices who will continue to apply the Katz test, four of whom will embrace the new approach outlined in Carpenter. Those four are Roberts, Breyer, Sotomayor, and Kagan. Based on his prior rulings and opinions, Justice Alito will likely continue to apply Katz, while scorning Carpenter.    

At least two Justices have already expressed their opposition to the Katz test: Thomas and Gorsuch. These Justices would prefer to interpret the Fourth Amendment on what they regard as more textualist grounds, limiting searches to the specific types of property--“persons, houses, papers, and effects”--mentioned in the Amendment. Thomas and Gorsuch differ dramatically, however, in terms of how expansive their property-based theories would be. Justice Thomas would confine the Fourth Amendment to traditional conceptions of property and only allow a person to challenge violations of their own property. This would drastically shrink the Fourth Amendment's scope and importance in the era of digital data. Justice Gorsuch, however, tends to support very robust Fourth Amendment protections in general, and has expressed interest in a capacious conception of Fourth Amendment property that encompasses, for instance, any business records that your cellphone service provider generates about your cellphone use. These might be considered your "papers" too, under Gorsuch's approach.

The positions of Justices Barrett and Kavanaugh are more difficult to predict. Justice Barrett has often likened her jurisprudential approach to that of her former boss, Justice Scalia. Scalia generally favored a more property-based approach to the Fourth Amendment. But, while he sometimes criticized the Katz test and its applications, he did not expressly call for Katz itself to be overturned, and my own informal conversations suggest that he did not support overturning it. This would be in keeping with his general approach to established precedents—unlike Justice Thomas, Scalia would not discard every case that conflicts with the original understanding of an amendment. I'd guess that Justice Barrett would take a similar tack, favoring a property-based approach where possible but not restricting the Fourth Amendment to tangible objects only. Her limited rulings as a lower court judge also suggest a fairly pro-Fourth Amendment alignment. For example, she once wrote that it was unreasonable for DEA agents to assume that a woman in a bathrobe who answered the door at a suspect’s residence had the authority to consent to a search of the premises—a fairly pro-privacy outcome in a non-obvious case. 

Justice Kavanaugh is often thought to approach issues in a similar fashion to Justice Kennedy, albeit with a more conservative lean. Kennedy generally applied the Katz test, but did so in a strict, pro-government fashion. Kennedy also generally favored a property-based approach, when possible, when applying Katz. Kavanaugh is reasonably likely to do the same. Indeed, his opinion in the Maynard GPS case suggesting that attaching a GPS device to a car might be a search because it was a trespass involving an “effect,” may have influenced Justice Scalia’s subsequent opinion in United States v. Jones adopting the same theory. I would guess that Justice Kavanaugh will ultimately take the Scalia approach as well, favoring a property-based approach where possible while not wanting to overturn Katz or declare nontangible data completely without constitutional protection. But, based on his opinions in lower court cases and his praise for Justice Rehnquist's pro-government Fourth Amendment rulings, he may do so in a less privacy-protective fashion than Scalia, leaning more towards Kennedy's pro-police approach.

What does this all mean for a future case involving, say, internet search histories, or recordings made by smart home speakers like Amazon's Alexa?

The future of Fourth Amendment search law may be fractured opinions. In cases involving invasive new digital technologies, there will typically be 4 votes to find a search based on the logic of Carpenter. Justice Gorsuch will likely concur separately, arguing that government collection of digital records trespasses on a suspect’s “papers,” despite these records being owned by a third party. The other Justices will probably dissent in many cases, though Barrett's vote is far from certain.

In cases involving a suspect’s house or particularly aggressive surveillance practices, Justice Barrett is fairly likely to join the majority, or Justice Gorsuch’s concurrence. Justices Alito and Kavanaugh may also join the majority in cases involving especially invasive or long-term surveillance. In close cases, like those involving area-limited facial recognition or information voluntarily disclosed to an app, Justices Roberts or Gorsuch may act as the swing vote, siding with the government. But the prospects for Fourth Amendment protection for digital data remain fairly bright.

As always, of course, the future of the Court is uncertain. And the composition of the Court could also change again before long.

Whichever way the Justices rule in future Fourth Amendment cases, the Court is likely to split in interesting and unusual ways, along multiple dimensions. These decisions may provide an interesting contrast to the many cases where the Court’s splits are both more predictable and more partisan.