Robert E. Lee was a traitor who served an immoral cause. But he was also a great general.

This bears note considering Lee’s treatment on Twitter following President Trump’s Friday explanation of why he equivocated on the 2017 white supremacist protests in Charlottesville, Va. Trump’s equivocation, he said, was motivated by some of the protesters’ affection for Confederate Gen. Robert E. Lee. And Lee, the president asserted, was a “great general, whether you like it or not.” That sparked a storm of tweets such as this one from New York Times columnist Charles Blow.