Wanting to have the last word, to write your own history or to speak at your own wake, is a natural human impulse. Former American presidents are afforded that licence, and more besides.
In a country lacking any real leadership from the sitting president, former presidents have a newly important role to play.
It's not just Trump. It's a different America.
Americans have moved beyond Abraham Lincoln’s optimistic view of Civil War reconciliation, perhaps forever. What would Lincoln say, if we could consult him, to a purge of Confederate monuments occurring in the year 2017?
What Trump is threatening is terrifying and senseless, but he is also America’s id, America’s bullying and brainless prowess unfiltered.