Edmund Morris, who died last week at 78, has the peculiar distinction of having written one of the best biographies of any American president, his three-volume life of Theodore Roosevelt published between 1979 and 2010, and one of the worst, his “official” life of the 40th president, Dutch: A Memoir of Ronald Reagan published in 1999. Let this be a lesson to biographers and presidents alike.

Morris was a graceful and perceptive writer. His life of Roosevelt, especially the first volume, The Rise of Theodore Roosevelt, which won the Pulitzer Prize in 1980, was not only a penetrating character study but did much to revive TR’s historic reputation, long overshadowed by his distant cousin Franklin. That, along with Morris’s conservative temperament and friendly feelings toward Reagan, seems to have persuaded such White House lieutenants as Michael Deaver, in the mid-1980s, to recruit Morris as Reagan’s authorized biographer. It was a gamble that didn’t pay off.