Obama’s DNC Speech Had a Hidden Message to Democrats

Experienced in the moment, Barack Obama’s speech to the Democratic National Convention in Chicago felt like the rousing culmination of a pep rally, peppered with funny insults of Donald Trump and familiar soaring patriotic oratory. But if you read it more closely, an argument emerges: against Trump and also against Obama’s own skeptics, including those within the Democratic Party who have turned away from his legacy.

Obama first electrified his party 20 years...