President Donald Trump views public life as a contest between dominant people and those they humiliate. The fact that he won the presidency under extraordinary circumstances, and without the popular vote, lingers in his mind because the question of who dominated whom remains ambiguous.

Every reminder that a stench of illegitimacy hovers over Trump’s administration has the capacity to unglue him. The need to resolve that ambiguity in his favor has consumed his presidency. This may turn out to be his undoing, but in the meantime it leaves the nation and the world vulnerable to the whims of an alarmingly unstable individual.

Greg Sargent of the Washington Post places the firing of FBI Director James Comey in the context of Trump’s obsession with his inaugural crowd size, his obsession with imaginary voter fraud, and other self-destructive outbursts, where it fits seamlessly.

The Comey letter to Congress about Clinton’s newly discovered emails is widely believed to have helped Trump win; Comey tacitly conceded that this might be true. The Russia probe continues to feed the sense that a foreign power helped tip the election to him; Comey won’t make it disappear. And, of course, there are lingering questions around the fact that Trump fired Comey right after he asked for more resources to prosecute that investigation, which of course would only further feed the sense that the Russian intervention mattered to the outcome.

What makes this analysis enticing is that it does not compete with other reported or plausible explanations for Trump’s decision—Comey’s unwillingness to submit loyally to Trump; his increasingly aggressive investigation of the Russia-Trump nexus; a coverup—or with Trump’s larger winners-and-losers worldview. Rather, they all reinforce one another.

What makes it so unsettling, meanwhile, is how profoundly it indicts Trump’s faculties. In his desperation to cast away the clouds that linger over his presidency, he has severely darkened them. Obstructing Comey’s investigation, and meddling in it repeatedly, has only compounded the suspicion that his campaign may have collaborated with Russian intelligence agents to sabotage the Clinton campaign. The president doth protest too much.