This piece was originally published on Just Security, an online forum for analysis of U.S. national security law and policy.

When President Donald Trump tweeted Monday that “the Caravan heading to the Southern Border” had “unknown Middle Easterners … mixed in,” the machinery of the federal government kicked in to reverse-engineer data to support his claim. The administration’s own numbers show that only a handful of people from the Middle East are apprehended at the southern border, far fewer than from other parts of the world too. Nonetheless, the president’s supporters quickly turned to trying to prove that terrorists (who they apparently equate with people from the Middle East, despite abundant examples of political violence from other groups) were flooding into the country from Mexico. Vice President Mike Pence doubled down on Trump’s statement, claiming:

In the last fiscal year, we apprehended more than 10 terrorists per day at our Southern border from countries referred to in the lexicon as ‘other than Mexico’—that means from the Middle East region.”

This precise assertion made it seem like Pence had data to back up his claim. In fact, his statement is consistent with the administration’s practice of dressing up prejudice as fact and mirrors other similar efforts, like its attempts to justify the Muslim ban.

Simply put: Pence’s statement is wrong and muddies government statistics so they fit the Trump administration’s narrative and mislead the public. The most obvious flaw with Pence’s statement is that his claim that the U.S. apprehends “10 terrorists per day” at the southern border is actually the statistic for all attempts to enter the U.S. A Pence spokeswoman conceded this point, but replaced it with yet another inaccurate statement: “In 2017 alone the U.S. apprehended on average between 10 suspected terrorists a day attempting to enter the country illegally.”

The vice president’s office seems to be conflating those actually apprehended at the border with a broader group of people that could include, for instance, those who were prevented from boarding flights overseas because they had been labeled a security concern. In public remarks and congressional testimony earlier this year, Department of Homeland Security Secretary Kirstjen Nielsen said that the department “prevents ten individuals with known or suspected terrorism connections a day from traveling to the United States and posing a potential threat to our homeland” [emphasis added]. Pence made another version of the same false claim with last year’s statistics—“along the southern border … we actually still apprehend … attempting to enter this country illegally … seven individuals a day who are either known or suspected terrorists.” There too, he seemed to be drawing from DHS data, which reported “encounters with individuals on the terrorist watchlist traveling to the United States” [emphasis added] attempting to enter by land, air, or sea.

Pence’s statement is wrong and muddies government statistics so they fit the Trump administration’s narrative and mislead the public.

As we’ve written before, the term “encounters” is ambiguous. The Justice Department has adopted a broad definition of “encounter,” which could cover “face-to-face” meetings at an airport or a preclearance station overseas, or it could mean a “paper-based” encounter, when an application for a visa or travel authorization turns up a positive hit on one of the government’s many watchlists. It may be that DHS uses a narrower definition than the DOJ. But in the absence of clarification, the 10-a-day number simply demonstrates that our vetting regime—which includes numerous checkpoints for flagging potential security threats before they can come into the U.S., perhaps even at the point when they’re applying to come in—is working.

Pence also exaggerated the terrorism threat posed by immigrants by conflating “terrorists” with the technical term “known or suspected terrorists on the watchlist” used by DHS. As we’ve also pointed out before, the watchlist—which contains over a million people—is vastly overinclusive. In the past, even Trump has agreed. When weighing in on legislation that would have prevented people on the watchlist from being able to buy guns, he said it had “a lot of people … that really maybe shouldn’t be on [it].” Indeed, the same lawmakers now pressing for measures to restrict immigration vigorously opposed that gun control proposal, citing “due process” and calling the list “notoriously inaccurate.” And they’re right when it comes to the watchlist. Government audits have found many thousands of inadequately supported listings. Indeed, watchlist problems have plagued everyone from the late Sen. Ted Kennedy, D-Mass., to the legendary musician Cat Stevens to 8-year-old American children.

This is but one example of the administration’s practice of laundering unsubstantiated claims by speciously grounding them in bureaucratic data. The press has generally done a good job of debunking these types of false claims. Courts too must be more wary than usual of the invocation of national security as a justification for the administration’s actions. The national security fig leaf is getting bigger—and its use more obvious. Pointing to “national security” should not automatically shield the administration’s actions from public and judicial scrutiny.

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