It has been almost four years since Donald Trump launched his presidential campaign from the gilded escalator of Trump Tower. In that time he has come to be feared by Democrats and Republicans alike for his personal attacks that always seem to supremely rile his opponents.
Now he has finally met his match.
Nancy Pelosi, the Democratic speaker of the House, has spent the past 48 hours doing to Trump what he has done to so many others. She lifted up his skin, got under it, and began scratching furiously.
Asked at her weekly news conference on Thursday whether she was concerned about the president's well-being, she replied: "I am," adding she was also concerned about "the well-being of the United States of America".
And then she delivered the coup de grace: "I wish that his family or his administration or staff would have an intervention for the good of the country. Maybe he wants to take a leave of absence."
Coming on top of the previous day's goading, in which Trump angrily flounced out of a White House meeting with her after Pelosi had accused him of being "engaged in a coverup", the House speaker's call for an intervention appeared to hit its mark.
Trump responded on Thursday by going on what can only be described as a Pelosi rant, at a White House event for farmers and ranchers. He began by showing the nation that he was in full possession of his faculties, contrary to the House speaker's insinuation, by proclaiming: "I am an extremely stable genius."
Then he proceeded to counter Pelosi's claim that he had "flipped out" and had a "tempter tantrum" at Wednesday's aborted meeting by insisting he had been calm. "I was so calm. I was extremely calm."
Lest there was any remaining doubt that he was entirely calm in the face of Pelosi's provocations, he paraded in front of the cameras a long line of White House staffers including his counselor Kellyanne Conway, strategic communications chief Mercedes Schlapp, press secretary Sarah Sanders and others and invited them to provide eye-witness accounts of his calmness.
Conway: "Very calm … you were very calm."
Sanders: "Very calm."
Schlapp: "You were very calm."
"I couldn't have been more calm," Trump concluded. In the course of the function Trump had uttered the word "calm" in a preternaturally calm voice to America's bemused farmers and ranchers no fewer than nine times.
Until this point in their fractious relationship, the US president has remained, by his standards, relatively respectful of Pelosi, sparing her the "Lyin' Ted"and "Crooked Hillary" jibes he has inflicted on hundreds of his perceived adversaries. But as a further indication of the effectiveness of the Pelosi taunt, he let rip on her on Thursday.
"She's a mess … she's disintegrating," he said. "I've been watching her for a long time. She's not the same person. She's lost it."
Then he called her "Crazy Nancy" before immediately regretting it. "I don't want to say 'Crazy Nancy' because if I say that you're going to say it's a copy of 'Crazy Bernie' and that's no good."
These past four years America and the world has got used to Trump forcibly having the last word. Not any more.
By end of play Thursday, Pelosi had logged on to Twitter - the social media platform of which Trump was supposed to be "master" - and scratched her nails under his skin one more time. "When the 'extremely stable genius' starts acting more presidential, I'll be happy to work with him on infrastructure, trade and other issues," she wrote.
Now what, Mr President?