When former President Obama left the White House, he pledged to take a back seat to make room for other Democrats in the party to shine. Nearly 17 months later, that’s proving to be an impossible task. Obama drew headlines this week after a Politico report revealed that he is consulting a long line of would-be 2020 candidates and offering advice to party leadership. And he drew another round of headlines when it was announced that his political committee, Organizing for Action, is revving up to help Democrats in the midterm elections. Democrats have turned to the party patriarch as...