"I may not be Donald Trump now, but just you wait; if I don’t make it, my children will.”

That is Obama now: a scholarly project, a figure of history. After the eight years of his presidency, it is odd to consider him in the past tense. Yes, he remains a public figure, as the mini-controversy over his speaking fees shows, and he is not going away, and certainly not with a post-presidential memoir still coming. But now he is fighting for history and legacy, and one of those battles is against another figure whose ascent is even more bizarre, yet perhaps no less personally preordained.

Obama had considered Donald Trump long before either man won the presidency, and brushed off his existence as a misguided national fantasy. Americans have a “continuing normative commitment to the ideals of individual freedom and mobility,” Obama wrote in the old Harvard book manuscript, now more than 25 years old. “The depth of this commitment may be summarily dismissed as the unfounded optimism of the average American — I may not be Donald Trump now, but just you wait; if I don’t make it, my children will.”