Last week I read a syndicated column reporting that Immigration and Customs Enforcement had arrested 15 suspected “Antifa” members for interfering with immigration enforcement activities. Embedded in this story was the columnist’s lazy and manipulative use of the label “Antifa.” America is full of activist groups. Left, right, center, environmentalists, gun owners, labor unions, business organizations, religious organizations, social organizations, veterans’ groups and countless others. They have names. Leaders. Membership lists. Websites. Phone numbers. Annual meetings. Dues. Go ahead and join any of them. But you know what group doesn’t have membership lists, officers, conventions, chapter presidents, newsletters, or membership applications? “Antifa.” You literally can’t...