“Keep Portland Weird”—that is a common slogan for Oregon’s largest city. But the rest of the country would rather at least one particular weirdness stay in Portland: Antifa, the radical-left extremist faction that has spent most of the summer and fall rioting there. But what is Antifa? Is it an idea, an ideology, or a conventionally understood group? Joining us to explore this question is writer Mark Hemingway, a third-generation Oregonian who conducted an in-depth analysis of Antifa for Real Clear Investigations.