Outgoing Homeland Security Secretary Alejandro Mayorkas said Sunday on ABC’s “This Week” that there had been a “significant increase” in the past 10 years of homegrown violent extremism. Mayorkas said, “We have a heightened threat environment, as Director Wray and the attorney general both articulated, and we’ve been saying this for quite a number of months. We have not only the persistent threat of foreign terrorism that, of course, created the Department of Homeland Security, but we have adverse nation-states, and for the past 10 years, we’ve seen a significant increase in what we term homegrown violent extremism. It is...