Nigel Hamilton is a bestselling biographer, his major subjects including John F Kennedy, Franklin D Roosevelt and Bill Clinton. His new book, Lincoln vs Davis: The War of the Presidents, was published on Tuesday, the US presidential election day when Kamala Harris faced Donald Trump. Late in his book, Hamilton notes a harsh 1862 verdict on Washington life by Adam Gurowski, a Polish emigre in the state department, anguished words that seem relevant and pungent today. “The political cesspool is deeper, broader, filthier and more feculent than ever,” Gurowski wrote. Gurowski had reason to be disgusted. In December 1862, the