... From Baltimore to New Orleans, cities across the South are removing statues of Confederate figures from public property — memorials often built as emblems of defiance to federal authority in the post-Reconstruction period and in the Warren Court years of the 1950s and ’60s. The white-supremacist and neo-Nazi rally in Charlottesville, Va., this month was occasioned by the city’s decision to take down a Robert E. Lee statue.

In the ensuing chaos, President Trump spoke of the “many sides” of the debate and defended the neo-Confederate view. “I wonder,” Mr. Trump said, “is it George Washington next week, and is it Thomas Jefferson the week after? You know, you really have to ask yourself, where does it stop?”

To me, the answer to Mr. Trump’s question begins with a straightforward test: Was the person to whom a monument is erected on public property devoted to the American experiment in liberty and self-government? Washington and Jefferson and Andrew Jackson were. Each owned slaves; each was largely a creature of his time and place on matters of race. Yet each also believed in the transcendent significance of the nation, and each was committed to the journey toward “a more perfect Union.”

By definition, the Confederate hierarchy fails that test. Those who took up arms against the Union were explicitly attempting to stop the American odyssey. While we should judge each individual on the totality of their lives (defenders of Lee, for instance, point to his attempts to be a figure of reconciliation after the war), the forces of hate and of exclusion long ago made Confederate imagery their own. Monuments in public places of veneration to those who believed it their duty to fight the Union have no place in the Union of the 21st century — a view with which Lee himself might have agreed. “I think it wiser,” he wrote in 1866, “not to keep open the sores of war.” ...