It’s a summer of sequels. The culture wars are back. So is the civil rights movement. So is the Civil War. They were all in evidence in Charlottesville, Va., on Aug. 12, when a protest over the planned removal from a city park of a statue of the Southern Civil War general Robert E. Lee exploded in violence. Two sets of protesters met and clashed: a battalion of white nationalists, neo-Nazis and Ku Klux Klanners and a crowd of counterprotesters, some with Black Lives Matter placards.

Then there was a second explosion, this one on the internet, when President Donald J. Trump responded to the fracas, after a significant pause, with an equivocating message. He blamed both sides for the violence (“What about the alt-left that came charging?”). He pronounced Robert E. Lee the equal of George Washington. He praised the “beauty” of the Lee statue and lamented the loss of other Confederate monuments

Other monuments were indeed under threat. The Charlottesville incident, and the president’s remarks, had created a consciousness-raising call to eliminate — or defend — statues associated with the Confederacy. A frenzied ideological war over visual images was underway. To the white nationalist protesters, Lee is a hero, his statue an emblem of a white dominance that is, in a steadily browning America, in decline. To the racially mixed counterprotesters, the same image is a reminder of a time when the South attempted to split the country in two to preserve black slavery.