The Fourth Amendment and the Color-Blind Constitution

When applying Fourth Amendment doctrine, to what extent can race and ethnicity be considered? The Supreme Court denied cert on Monday in United States v. Carter, a case on this question—specifically, on whether the Fourth Amendment test for whether a person is “seized” factors in the person’s race.  There’s an interesting connection between this issue and last fall’s debate over the role of race in immigration stops, raised in Noem v. Vasquez Perdomo. I thought it might be worth flagging the potential connection, and to ask about ways to distinguish how the law approaches them.

Here’s the context.  Carter asked the Court to resolve a longstanding open question in Fourth Amendment law: When applying the Fourth Amendment test for when a person is seized—whether a reasonable person in that situation would feel free to terminate the encounter and leave—does the suspect’s race matter?  There’s a split among lower courts. Some courts say that there is one reasonable person standard for people of any and all races.  Other courts say that people of different races tend to have different experiences with the police, and that those different experiences can can lead to a different sense of when they are free to leave. Under the first approach, race is irrelevant; under the second approach, race is relevant.

Justice Alito dissented from the denial of certiorari, joined by Justice Thomas.  Justice Alito’s dissent raised the question of whether a broader commitment to a color-blind Constitution answered the question in Carter:

We have said that our “‘Constitution is color-blind.'” Students for Fair Admission, Inc. v. President and Fellows of Harvard College, 600 U. S. 181, 230 (2023). It “almost never” allows government actors to treat persons differently based on their race. Louisiana v. Callais, 608 U. S. ___, ___ (2026) (slip op., at 17). And we have rejected the proposition that the Constitution permits an individual to be treated differently based on a “perception that members of the same racial group—regardless of their age, education, economic status, or the community in which they live—think alike.” Shaw v. Reno, 509 U. S. 630, 647 (1993). It is dangerous to allow an individual to be treated differently based on statistics, studies, or expert testimony that purports to show that members of the racial or ethnic group to which he belongs are more likely to act in a certain way than are members of other groups. Here, the special treatment helped the individual; in other situations it will not. See Buck v. Davis, 580 U. S. 100, 119 (2017).

Perhaps the [lower court’s] test has legitimate justifications. In any event, it is important, and it warrants this Court’s review. I therefore respectfully dissent from the denial of certiorari.

I don’t take Justice Alito to have answered the question of whether a commitment to a color-blind Constitution requires saying race is irrelevant to the seizure analysis, as he was just flagging the question as important and cert-worthy (which seems right to me).  Still, Justice Alito’s opinion suggests at least that it might do so.  And that view has surfaced in some of the lower court caselaw, such as Judge William Pryor’s opinion in United States v. Knights, 989 F.3d 1281, 1289 (11th Cir. 2021).

Which brings me to my question: If you believe that a commitment to a color-blind Constitution answers the question in Carter, does it also answer whether race can be used as a basis for cause in making a stop for immigration violations, one of the big questions debated last fall when the Court was considering in Noem v. Vasquez-Perdomo?

As you may recall from Noem, one of the issues involved in reviewing that injunction was the use of race and ethnicity to temporarily stop people for immigration violations, which was a major question in light of ICE enforcement activities.  That wasn’t a new issue in Fourth Amendment law, to be clear.  Back in 1975, in United States v. Brignoni Ponce, the Court had held that a person’s perceived Mexican ancestry was relevant to whether to stop them for a possible immigration violation but not enough cause on its own.  Brignoni Ponce concluded: “The likelihood that any given person of Mexican ancestry is an alien is high enough to make Mexican appearance a relevant factor, but standing alone it does not justify stopping all Mexican-Americans to ask if they are aliens.”

In Noem, last fall, that holding was relied on in parts of Justice Kavanaugh’s concurrence explaining his vote in favor of the stay of the district court’s injunction.  That led some to treat Justice Kavanaugh’s opinion as the source of that approach, although I think it goes back to 1975 and Justice Powell’s opinion for the Court in Brignoni Ponce (which was joined by Justices Marshall and Brennan, among others).  And although this isn’t a post specifically about Justices Alito and Thomas, it’s perhaps worth flagging (given their dissent on Monday in Carter) that we can’t be sure that they agreed with Justice Kavanaugh’s reliance on Brignoni Ponce for the stay in Noem, but that it seems at least plausible to surmise that they did.

The broad question I want to flag is whether there is a principled basis for saying that the color-blind Constitution forbids use of race in the Fourth Amendment seizure test in Carter, but that it allows use of race in Fourth Amendment doctrine in determining if there is cause to seize someone in a case like Noem?  And consider the flip side of it, too: Is there a principled basis for saying that the color-blind Constitution allows use of race in the Fourth Amendment seizure test, but that it forbids use of race in Fourth Amendment doctrine in determining if there is cause to seize someone?   More broadly, does the answer to whether the doctrine can account for race, and derive different answers based on race, have to be the same in these two doctrinal contexts?

To be clear, I think there are entirely plausible arguments for getting to different answers in these two contexts internally to Fourth Amendment doctrine.  Doctrinally, the reasonable suspicion test is empirical, and the seizure standard is an objective test.  The two tests occupy different doctrinal space, and they serve different functions.  It’s entirely plausible that race would be relevant in one setting but not in the other just as a matter of “normal science” working through the doctrine.

The issue flagged by Justices Alito and Thomas in Carter strikes me as broader, though.  They seem to be asking not just what is the right answer as a matter of Fourth Amendment doctrine, based on the particular tests at issue, but rather suggesting that the Constitution has a broader color-blind commitment that cuts across doctrines and makes reliance on race when applying constitutional tests problematic generally.  My question is, if you use that premise as your starting point, do you have to come to the same answer in Carter and Noem?  And if not, how do you distinguish the two contexts?