President Donald Trump held a roundtable on Wednesday, which featured prominent administration officials and independent journalists, billed as a “Roundtable on antifa.” Much of the commentary at the event, which lasted more than 90 minutes, focused on Portland and other cities where Trump has attempted to or succeeded in bringing in federal troops to quell protests. Antifa, short for “anti-fascists,” is used to broadly describe militant, far-left-leaning groups. Outside the U.S. Immigration and Customs Enforcement building in South Portland, where protests have been happening since June, a large share of protesters at night are dressed in black bloc to conceal...