Trump's grudges are his agenda

On policy, Trump is inattentive and inconsistent. Where he’s attentive and consistent is in his personal attacks on his adversaries. Trump’s presidency will have vast and frightening policy implications, most which he doesn’t understand. But Trump’s primary goal as president does not appear to be enacting a set of policies; his behavior suggests that his real goal is feeding his ego and vanquishing his enemies. He’s only truly interested in his presidency’s impact on himself. Calling Bill Clinton’s affair with Monica Lewinsky a diversion made sense because Clinton was genuinely committed to certain policy goals, which he undermined by his personal recklessness. With Trump, personal recklessness is all there is.

That’s why Trump will launch attacks like the one he launched against Mika Brzezinski for as long as he’s president, and likely after that. Saying he attacks people viciously because he lacks impulse control is like saying a professional boxer lacks impulse control because he punches people in the ring. For Trump, this is the true purpose of politics, if not life itself.