 You would want to say the president. Okay, we'll say the president. But next to the president, who's the most powerful person in the White House? Well, the chief of staff, of course. And that person, he or she, controls the flow of everything in the White House on behalf of the president. So he or she is the gatekeeper to the president, coordinating all the memos, all the briefings from the CIA, all the briefings from the intel community.