It was no secret during the campaign that Donald Trump was a narcissist and a demagogue who used fear and dishonesty to appeal to the worst in American voters. The Times called him unprepared and unsuited for the job he was seeking, and said his election would be a “catastrophe.”

Still, nothing prepared us for the magnitude of this train wreck. Like millions of other Americans, we clung to a slim hope that the new president would turn out to be all noise and bluster, or that the people around him in the White House would act as a check on his worst instincts, or that he would be sobered and transformed by the awesome responsibilities of office.

Instead, seventy-some days in — and with about 1,400 to go before his term is completed — it is increasingly clear that those hopes were misplaced. In a matter of weeks, President Trump has taken dozens of real-life steps that, if they are not reversed, will rip families apart, foul rivers and pollute the air, intensify the calamitous effects of climate change and profoundly weaken the system of American public education for all. His attempt to de-insure millions of people who had finally received healthcare coverage and, along the way, enact a massive transfer of wealth from the poor to the rich has been put on hold for the moment. But he is proceeding with his efforts to defang the government’s regulatory agencies and bloat the Pentagon’s budget even as he supposedly retreats from the global stage.

These are immensely dangerous developments that threaten to weaken this country’s moral standing in the world, imperil the planet and reverse years of slow but steady gains by marginalized or impoverished Americans. But, chilling as they are, these radically wrongheaded policy choices are not, in fact, the most frightening aspect of the Trump presidency.

What is most worrisome about Trump is Trump himself. He is a man so unpredictable, so reckless, so petulant, so full of blind self-regard, so untethered to reality that it is impossible to know where his presidency will lead or how much damage he will do to our nation. His obsession with his own fame, wealth and success, his determination to vanquish enemies real and imagined, his craving for adulation — these traits were, of course, at the very heart of his scorched-earth outsider campaign; indeed, some of them helped get him elected. But in a real presidency in which he wields unimaginable power, they are nothing short of disastrous. ...