Conservatives must learn the lessons of 2020—and prepare. The resurgence of public protests in support of Hamas has revealed a disturbing truth: the left-wing rioting following George Floyd’s death in 2020 was not an anomaly, but a tactic that activists can repurpose for any cause. Whether by coincidence or design, these recent outbursts could be a dress rehearsal for possible violence during next year’s election campaign. Conservative leaders must prepare for that prospect. To prevent 2020 from repeating itself in 2024, conservatives need to consider what might spark a riot, how it can be prevented, and how to understand and...