President Donald Trump’s chief of staff Susie Wiles offered a remarkably candid window into a presidency she described, repeatedly, as driven by impulse and a widening view of executive power, in a blockbuster Vanity Fair portrait built around months of exclusive on-the-record conversations. Wiles may be the most powerful figure in Trump’s West Wing besides Trump himself, but her role is exercised less as a brake than as a gearbox, translating the president’s instinct into policy, and urging everyone else to fall into line. “I’m not an enabler. I’m also not a bitch,” Wiles said. “I guess time will tell...