Claims of a Russian conspiracy and the unfairness of the Electoral College shielded Mrs. Clinton from ever truly conceding she had lost. She was robbed, she told herself, yet again. But after two years of brooding—including at book length—Mrs. Clinton has come unbound. She will not allow this humiliating loss at the hands of an amateur to end the story of her career. You can expect her to run for president once again. Maybe not at first, when the legions of Senate Democrats make their announcements, but definitely by the time the primaries are in full swing.

Mrs. Clinton has a 75% approval rating among Democrats, an unfinished mission to be the first female president, and a personal grievance against Mr. Trump, whose supporters pilloried her with chants of “Lock her up!” This must be avenged.

Expect Hillary 4.0 to come out swinging. She has decisively to win those Iowa caucus-goers who have never warmed up to her. They will see her now as strong, partisan, left-leaning and all-Democrat—the one with the guts, experience and steely-eyed determination to defeat Mr. Trump. She has had two years to go over what she did wrong and how to take him on again.