U.S. citizens were 80.2 percent of border crossers carrying fentanyl at border crossings from 2019 to 2024

David J. Beer

Many people mistakenly believe that immigration is crucial to the illicit supply of fentanyl into the United States. However, proponents of this view have offered little more than speculation to support their claim. New data obtained by the Cato Institute through a Freedom of Information Act (FOIA) request casts doubt on this belief. The new dataset shows that U.S. citizens made up 80 percent of those caught with fentanyl at ports of entry from 2019 to 2024.

The FOIA dataset contains individual data on every individual encountered by officers at U.S. border crossings from whom fentanyl was seized. Figure 1 shows the citizenship status of individuals arrested with fentanyl from fiscal year (FY) 2019 to 2024, as of June. Overall, the dataset reveals that of the 9,473 individuals linked to a fentanyl seizure, 7,598 were U.S. citizens (80.2 percent).

The data are most relevant to understanding fentanyl seizures because the vast majority of fentanyl is seized at ports of entry, not between ports of entry where people cross illegally. Figure 2 shows fentanyl seizures by location. From FY 2015 to 2024, 88 percent of all fentanyl was seized at ports of entry, essentially the same as in FY 2024. Another 4 percent was seized during vehicle stops on interstates after the ports. Only 8 percent were seized by Border Patrol while on patrol, and many of those seizures also came from vehicle stops. The seizure data support the qualitative assessments of the Drug Enforcement Agency, Customs and Border Protection (CBP), and the Office of National Drug Policy based on investigative work. Even Bill Barr, when he was attorney general under President Donald Trump, agreed.

Drug trafficking organizations hire U.S. citizens because they have the right of entry into the United States and are subject to fewer port-of-entry checks than noncitizens. Data from the U.S. Sentencing Commission reinforces the impression that U.S. citizens are the primary method of cross-border fentanyl trafficking. From 2018 to 2023, U.S. citizens accounted for 2,315 of the 2,905 convicted drug traffickers in the southwest border districts (80 percent). The number of U.S. citizens involved in fentanyl trafficking has increased faster than the number of other traffickers since 2018.

Of course, these statistics don’t include the drugs that evaded detection or the traffickers who weren’t caught. But just as surveyors don’t have to interview everyone in the country to know that the country is politically divided, we don’t have to see everyone crossing the border to draw conclusions about broad trends. Border Patrol apprehensions of immigrants crossing the border illegally provide a significant sample size from which to draw any reasonable conclusions about the invisible market.

From October 2018 through June 2024, Border Patrol made 8.5 million arrests and recorded 1,341 “seizures” of fentanyl. It is likely that half of these were U.S. citizens apprehended in vehicles at Border Patrol checkpoints or while patrolling the highway. Border Patrol also finds and records abandoned fentanyl as “seizures.” It appears that fentanyl seizures occur in fewer than 1 in 12,000 Border Patrol encounters with immigrants crossing the border. Fentanyl smuggling is relatively rare among the border-crossing population, and the flows that evade detection are far smaller than the number that are apprehended.

It makes sense to hire smugglers to move drugs through legal border crossings because the chances of detection are much higher at illegal crossings. CBP estimates that it seized only 2.98 percent of cocaine, the only drug it analyzed, that went through U.S. border crossings. This compares to its interdiction effectiveness rate for immigrants crossing illegally of more than 75 percent (Figure 4). Even if CBP is much less effective at stopping border crossings than it thinks, there is still an incentive to try to smuggle at border crossings.

Eliminating immigration will not end fentanyl smuggling

Many people think that simply eliminating immigration is an easy answer to the overdose crisis in the United States, but these numbers throw cold water on that strategy. In fact, the overdose crisis worsened significantly in the years when legal and illegal immigration were severely restricted (Figure 5). In 2020, when immigration of all types was radically restricted by President Trump, fentanyl overdose deaths rose 56 percent. They rose another 22 percent in FY 2021 as President Biden maintained Trump’s restrictions on legal entry and attempted to enforce his Title 42 asylum ban.

The travel ban at ports of entry was instrumental in facilitating the increase in fentanyl supply, which led to more deaths. U.S. consumers favored heroin through 2020, but with severely restricted travel, cartels had to move more product with fewer trips. Fentanyl made this possible. Because it is 50 times more potent than heroin, it can supply the same market with 50 fewer crossings. As a result, fentanyl went from a third of combined fentanyl and heroin seizures to more than 90 percent when the travel ban ended, where it remains (Figure 6).

Fentanyl is relatively easy to conceal in pockets, luggage, and vehicles because it is so potent. The prospect of easy money has motivated a growing number of Americans to participate in this illicit trade, which has tragically led to the deaths of thousands of our countrymen.

Detection technology is not the answer

Many people suggest that we should install more effective screening tools at ports of entry to detect and interdict fentanyl. Unfortunately, better detection technologies are not the answer to America’s drug problem. We have several lines of evidence that support this conclusion.

First, marijuana was successfully smuggled into the United States for decades, despite being far easier to detect than any other drug. Marijuana is bulky, pungent, and extremely difficult to conceal. For this reason, it largely could not enter through legal channels. It is also worth far less per pound, so there is less financial benefit to smuggling. Nevertheless, as I describe in my policy analysis on the subject, nothing has reduced marijuana smuggling—not doubling the Border Patrol, not building 600 miles of fence, not the collapse of illegal immigration during the Great Recession. It was only when the state legalized that the supply of Mexican marijuana disappeared. Changes in consumer demand ended the trade, not enforcement.

Second, an unprecedented increase in seizures would not affect the availability of fentanyl unless drug cartels choose not to increase supply. We already know they will. After the Border Patrol more than doubled in size, marijuana seizures increased along with that increase, but the availability of marijuana remained the same and its potency increased. Since the value of drugs on the Mexican side of the border is at most one-tenth that of drugs on the U.S. side, the interdiction rate would have to increase from the current 3 percent to nearly 90 percent to double the price. But thanks to increased production in Mexico, the price of fentanyl has fallen so quickly that this historic effort would not necessarily be reflected in a higher street price.

Third, there is almost no limit to how potent synthetic opioids can become. Even if CBP were to achieve a much higher detection rate for fentanyl, drugmakers could quickly switch to nitazenes, which are already emerging in the United States and are 20 times more potent than fentanyl. Nitazenes could supply the same fentanyl market with 5 percent of the current number of smuggling trips (or 5 percent as much by weight). Of course, causing such a shift would potentially result in even more tragedies. But shifts like this have happened repeatedly in the drug market, including the shift from heroin to fentanyl.

Fourth, in the unlikely event that the Mexican smuggling routes were to be cut off, smugglers would use other methods. They would send it in parcels, as they had done before the rise of Mexican smuggling. Supposing all smuggling were to stop, Americans would simply produce it domestically. Where there is demand, there will be supply.

Conclusion

Policymakers should focus on reducing the demand for fentanyl rather than trying in vain to reduce the supply. Cato scholars who predicted the fentanyl crisis have proposed many concrete ideas that don’t necessarily amount to ending drug prohibition itself: Legalize fentanyl test strips to allow drug users to exclude fentanyl. Eliminate screening for methadone treatment. Allow doctors to treat addiction without risk of jail time or loss of their medical license. Reschedule diamorphine to allow its use in treatment.

People are so distracted by immigration as an easy fix for fentanyl that they ignore real solutions. People are dying because politicians have decided that empowering cartels to flood the market with fentanyl is better than deregulating addiction treatment, which would then dry up the demand for illegal drugs. Other countries have adopted better drug policies and achieved better results. None of those results came from restricting immigration.