What’s impossible to divine is Whitaker’s thinking. Before joining the Justice Department last year, Whitaker, a former U.S. attorney from Iowa, sounded skeptical about Mueller. He raised the notion of the investigation being a “fishing expedition.” Whitaker also used one of Trump’s stock criticisms of Mueller’s work: “witch hunt.” Yet there’s a big difference between opining as a private citizen and opining after being appointed, even temporarily, the nation’s chief legal officer. We presume Whitaker understands the stakes and his obligation to the Constitution, even if Trump sounds unclear on the concepts. Whitaker is scheduled to be on the job for up to 210 days.