At times during the campaign, Mr. Obama has sought to gird his message of hope with more references to his concrete proposals, but more often he has seemed to discount the importance of such specificity, and this has enabled Mrs. Clinton to portray him as insubstantial. Mrs. Clinton, meanwhile, has at times seemed to regard the very notion of transformative change as Pollyannish and silly, conveying instead the idea that government is all about metrics and practicality.

Mr. Axelrod’s storytelling has created a dynamic hero who sometimes seems estranged from the practicalities of governing; Mr. Penn’s data has created a credible platform put forth by a candidate whose theory of leadership can seem small. What voters love in one they crave in the other.