America’s culture wars came to London last week. Donald Trump likes to bring disruption with him. During his state visit, he also brought his extraordinary ability to drive his opponents to physical violence.

Anti-Trump mobs, modeled on their American equivalents, whipped themselves into what can only be called an ecstasy of odium. “No to hate!” they chanted, their faces contorted with hate. “No to intolerance!” they added, hurling milkshakes at people they imagined might not share their views.