When President Donald Trump gave his first address to a joint session of Congress in February of 2017, he claimed that “the vast majority of individuals convicted of terrorism and terrorism-related offenses since 9/11 came here from outside of our country,” citing “data provided by the Department of Justice.”

Not only was that claim not true, but there was no data from the Department of Justice to back it up.

In response to a Freedom of Information Act request from a private lawyer, the Justice Department admitted recently that “no responsive records were located” after an exhaustive search for evidence to substantiate Trump’s claim.

It’s hardly the first time that Trump has been found to have said something incorrect. A recent count by the Washington Post reveals that he’s made 4,229 false or misleading claims since taking office, an average of nearly 7.6 per day.

But presidential scholars and former White House staffers say that it’s rare for a president to make a false statement during a speech to Congress, much less to cite nonexistent research from his own Cabinet to support it. It’s even worse, they say, that it was used to justify a major policy proposal outlined in the speech.

During the address, Trump called it “reckless” to allow “allow uncontrolled entry from places where proper vetting cannot occur,” an apparent reference to his Administration’s controversial travel ban on several Muslim-majority countries. He released a revised version of the executive order about a week later.

Barbara Perry, the director of presidential studies at the University of Virginia’s Miller Center, pointed to a categorization system created by James Pfiffner that ranks different types of political deception by severity.

“To base a policy on a, quote, fact or statistic that I presume he knows is false, or someone who wrote that statement for him knows is false — to me that’s the worst of all,” she said.

When asked by fact-checkers for evidence to support Trump’s statistic, the White House pointed to a Fox News report which cited research from a Senate subcommittee led by Jeff Sessions, an Alabama senator who later became Trump’s attorney general.

But there are several ways in which that research did not back up Trump’s claim: It was about charges from 9/11 through the end of 2014, the list of offenders it obtained from the Justice Department did not include their birthplace or immigration status, and the convictions were only based on investigations into international terrorism. Only a small minority of the cases involved terrorist acts planned or executed within the United States, and many of the convictions were for non-terrorism-related offenses such as identity fraud and immigration violations.

PolitiFact rated Trump’s claim in the speech “Mostly False” and the Washington Post gave it a maximum of “Four Pinocchios.”

The statistic also caught the eye of Benjamin Wittes, an American journalist who writes primarily about national security and law. He is the co-founder and editor-in-chief of Lawfare, a blog dedicated to reporting on national security issues and choices.

Wittes suspected that the Justice Department didn’t even have aggregate terrorism data that included all of its domestic occurrences. “That’s just not a category of data that people keep,” he said. But America suffers from “a lot” of domestic terrorism, he noted, citing examples like the Oklahoma City bombing in 1995 or the Charleston church shooting in 2015.

He thought Trump was wrongly conflating international terrorism with terrorism in general. “It’s a very pernicious thing to do because it’s a way of saying the terrorism problem is a problem with immigration,” he said.

He requested the Justice Department provide records on the claim under the Freedom of Information Act, eventually filing a lawsuit when he did not receive a response. As part of a legal agreement settling the case, the Justice Department agreed to search for pertinent records on data about all terrorism offenses and could not find any documents.

“I never doubted for a minute the data to support the President’s statement didn’t exist,” said Wittes. “Is there a sense of vindication? Sure, there’s a sense of vindication. Was I surprised? Absolutely not.”

To be fair, some past presidents have also made misstatements in major Congressional addresses. In 16 infamous words during his 2003 State of the Union, George W. Bush falsely stated that “Saddam Hussein recently sought significant quantities of uranium from Africa.” The claim was later debunked. More recently, Barack Obama said during a 2009 speech to Congress that his health care reforms would not require people to change their current insurance. “Let me repeat this: nothing in our plan requires you to change what you have,” he said. That was a misrepresentation of his policy and proved untrue.

The White House never corrected the record on Trump’s speech. Later, as part of Trump’s rollout of the second version of the travel ban, he requested that the Departments of Justice and Homeland Security release data on “foreign nationals” who were charged with terrorism-related offenses. In January 2018, the Justice Department did so, putting out a report which found that approximately 73% of individuals “convicted of international terrorism-related charges” were foreign-born.

The data did not include domestic terrorist acts and the report acknowledged that limitation, noting that it “does not include individuals convicted of offenses related to domestic terrorism…”.

Trump then tweeted out a reference to the report in which he again misstated the data, leaving out the fact that it only included international terrorist acts and not domestic offenses. The Washington Post again gave the claim its maximum score of “Four Pinocchios.”

Mary Kate Cary, who worked as a speechwriter for President George H.W. Bush from 1989 to early 1992, said that speeches to Congress are typically given the highest-level of fact-checking within the White House.

“It was one researcher one speechwriter for every speech,” she recalled. “Then, once you wrote it, the researchers would fact check literally every word and, in those days, they had to put a check mark over every word.”

Both the researcher and the speechwriter would put their name at the top of the draft, so that there would be accountability in the case of an error. After that, the speech would go to all of the senior staff members at the White House. It was also sent to Cabinet members whose agencies were pertinent to facts or policies mentioned in the speech.

The research office even kept a piece of paper noting how many days it had been since they had gotten a fact wrong.

As a speechwriter, Cary explains why she has long been committed to correctness. “Well all speechwriters – you know, we’re biased – but all speechwriters think that words matter and facts matter,” she laughed. “And that you are creating, especially in the office of the president, a historical record of what the United States policy is at the time. And that’s why it’s important to make sure that everything is factually accurate, you know, in line with administration policy – all those sort of things.”

“Because sometimes statements are innocuous – and believe me, I wrote my share of turkey pardonings — but sometimes statements are very, very important and can affect peoples lives,” she added.

Wittes said it was worthwhile spending a year and a half proving that Trump’s claim was inaccurate.

“It matters what the president of the United States says,” he said. “It matters whether you can trust the words that come out of his mouth.”

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