Antifa, as described in the national security presidential memorandum (NSPM), is both everything and nothing. It is in forums and social media and in-person meetings. It is in educational organizations and nonprofit institutions. It is protests (“riots”) not just in Portland, but in Los Angeles as well, whether against Trump’s immigration policies or, separately, “anti-police and ‘criminal justice’ riots.” It is the doxxing of masked and armed ICE agents. It is the…