Seamus Hughes, the deputy director of George Washington University’s Program on Extremism, tracks detailed data on people “arrested, indicted, or convicted in the United States for ISIS-related activities.” I asked Hughes for data on the citizenship status of all 105 cases of all individuals charged with ISIS-linked crimes in the United States.
According to Hughes, the vast majority — 85 people, or 81 percent of the total — were US citizens. Eight were permanent residents, three were refugees, and one was undocumented (eight more could not be confirmed)
This data shows that the overwhelming majority of domestic ISIS sympathizers were either born in the US or had been living here for a very long time before turning to terrorism. (The average time to go from a green card to US citizenship is seven years.)