“I just found the book that strike fear in the heart of Donald Trump,” Rep. Keith Ellison (D-Min.), Deputy Chair of the Democratic National Committee, tweeted on Wednesday, and attached his selfie holding up a copy of “Antifa: The Anti-Fascist Handbook,” by Mark Bray. This is worrisome, especially should the anticipated Democratic “wave” materialize in November, 2018. Because, even as reflected through Bray’s book, Antifa in the US are self-appointed gangs on the hunt for their natural enemies—whomever they decide they are—and, like a gang, they have no problem using violence. A senior DNC official must not advocate these tactics....