Donald Trump says hundreds of migrants and their children have been implicated in U.S. terrorism

The mass shooting in Orlando is further evidence the United States shouldn’t accept immigrants from the conflict-torn Middle East, says Republican presidential candidate Donald Trump.

"We admit more than 100,000 lifetime migrants from the Middle East each year," Trump said in a June 12 statement. "Since 9/11, hundreds of migrants and their children have been implicated in terrorism in the United States."

Though not an immigrant, the Orlando shooter Omar Mir Saddique Mateen declared allegiance to the Islamic State before killing 50 and injuring dozens in a gay nightclub. Mateen, who was killed in a SWAT raid, was a U.S.-born citizen, but his father is an immigrant from Afghanistan and has expressed some Taliban sympathies.

We were curious if Trump has his numbers right — that "hundreds of migrants and their children" have engaged in terrorism in the United States since the World Trade Center attacks in 2001.

We’re treating the word "migrant" as a broad category including anyone who moves to the United States. And "terrorism" includes individuals who successfully carried out attacks but also people involved in plotting, funding and other activity connected to terrorism.

Given those definitions and the best information we have at our disposal today, Trump’s claim is potentially accurate but draws a questionable conclusion.

The number of individuals implicated in jihad-inspired U.S. terrorist activity since 9/11, who are immigrants or children of immigrants, is likely somewhere between 140 and 300, based on the latest New America Foundation research.

The next day, June 13, Trump said, "The Senate Subcommittee on Immigration has already identified hundreds of immigrants charged with terrorist activities inside the United States since September 11th." We reached out to the staff of Sen. Jeff Sessions, R-Ala., chair of the Senate Subcommittee on Immigration and the National Interest, to find out more about this supposed list of hundreds of immigrants charged with terrorist activities that Trump mentioned. Sessions’ office would not comment on the record.

But the New America Foundation, a think tank, has compiled a database of people charged with or who are credibly believed to have been engaging in extremist activity in the United States. The New America Foundation has documented 505 individuals involved in some sort of terrorist activity since 2001. The majority, 323, were jihad-inspired, while the remaining 182 are believed to have been driven by some other ideology.

Of the jihadist group — the one most pertinent to Trump — at least 139 of the documented individuals were born outside the United States and then migrated there. The rest were either born in the United States, or their immigration status is unknown.  

The database does not identify who among the 149 natural-born citizens engaged in jihadist terrorism in the United States has migrant parents. But anecdotally, we are aware of some. Here are a few high-profile examples:

• Omar Mir Saddique Mateen, the Orlando shooter, was born in the United States, and his father is an immigrant from Afghanistan.

• Syed Rizwan Farook, one of two terrorists in the Dec. 2, 2015 San Bernardino shooting, was born in the United States to parents who immigrated from Pakistan.

• Nidal Malik Hasan, the shooter in the 2009 Fort Hood attack, was born in the United States to Palestinian immigrants.

So definitely more than 140 people accused of jihad-inspired terrorism fit Trump’s bill, as "migrants and their children." But it’s unclear if the actual number is high enough to be "hundreds."

This statistic doesn’t support Trump’s assertion that the United States should ban Muslim immigrants, though, said David Sterman, who researches homegrown extremism at the New America Foundation. Most domestic terrorists were either born in the United States, or they came to the United States at a very young age, so they spent their whole lives here.

"It’s really misleading to portray the terrorist threat inside the U.S. as primarily foreign, when in fact it’s primarily domestic, inspired by foreign terrorist organizations," Sterman said.

William Banks, director of Syracuse University’s Institute for National Security and Counterterrorism, said it’s important to note that the number of violent jihadist terrorism attacks is tiny compared to other violent acts in the United States. The New America Foundation database counts 10 lethal jihadist attacks on American soil since 9/11.

And when Trump talks about "migrants and their children," he’s talking about a sizeable share of the country’s population. About 76 million people in the United States — about a quarter of the total population — are either immigrants or children of immigrants as of 2013, according to the Pew Research Center.

This group includes Trump himself, as his mother immigrated to the United States from Scotland.

Our conclusion

Trump said, "Since 9/11, hundreds of migrants and their children have been implicated in terrorism in the United States."

Based on the research we have available, about 140 migrants have been charged with or are credibly believed to have been involved in jihadist extremist activity in the United States since the World Trade Center attacks. Some number more — up to a maximum of 184 additional individuals — are children of immigrants. Those numbers may be incomplete but are the best available at this time.