Brazil’s ‘January 6 Moment’ Is a Warning

The threat from authoritarian populists endures.

Three days ago, cable-news channels marked the second anniversary of the assault on the U.S. Capitol by replaying videos taken on January 6, 2021. Anybody who watched CNN on Friday would have seen hours of footage of protesters breaking through thin police lines, storming the Capitol, and wreaking havoc in the symbolic center of American democracy.

This made the videos broadcast yesterday afternoon look eerily familiar. Once again, protesters easily broke through a thin line of police. Once again, thousands of people stormed key...