Normal leaders come up with policy proposals in a certain conventional way. They gather their advisers around them and they debate alternatives — with briefing papers, intelligence briefings and implementation strategies.

Donald Trump doesn’t do that. He’s tweeted out policy gestures in recent weeks, say about the future of America’s nuclear arsenal. But these gestures aren’t attached to anything. They emerged from no analytic process and point to no implemental effects. Trump’s statements seem to spring spontaneously from his middle-of-night feelings. They are astoundingly ambiguous and defy interpretation.

Normal leaders serve an office. They understand that the president isn’t a lone monarch. He is the temporary occupant of a powerful public post. He’s the top piece of a big system, and his ability to create change depends on his ability to leverage and mobilize the system. His statements are carefully parsed around the world because presidential shifts in verbal emphasis are not personal shifts; they are national shifts that signal changes in a superpower’s actual behavior.

Donald Trump doesn’t think in that way, either. He is anti-system. As my “PBS NewsHour” colleague Mark Shields points out, he has no experience being accountable to anybody, to a board of directors or an owner. As president-elect, he has not begun attaching himself to the system of governance he’ll soon oversee.