When the President released a video shortly after the vote he didn't even mention it. Instead, in a performance labelled as "teleprompter Trump", he condemned last week's violence and appealed for calm ahead of President-elect Joe Biden's inauguration less than a week from now.

Trump's administration has also, uncharacteristically, been playing a little more nicely with others over the past few days, even telling the Bidens they can move into Blair House at 1651 Pennsylvania Avenue, just down the road from the White House.

So, why the change from the frenetic and inflammatory behaviour people have come to know and expect? One reason is that Trump has had a while to get used to the idea of impeachment. It was inevitable, as was the case last January, that if an impeachment motion was put in the wake of last week's incitement to insurrection, it would be passed. The only surprise was that 10 Republicans had the courage to vote with the Democrats.

The second reason is that, despite his infamous impulsiveness, Trump is capable of calculation. He didn't accidently become President. Right now he would be thinking about how his own interests can be best served, even from this historically dire situation. His main concern is not the taint of having been the first US president ever to be impeached twice. It is the likelihood that if the 17 upper house Republicans required to meet the necessary two-thirds majority vote to convict, the Senate could then vote to bar him from standing for federal office ever again. He would also lose the pension and travel perks that come the way of former presidents.

Thursday's uncharacteristically responsible speech worked on a number of levels. It was, first and foremost, directed at Senate leader Mitch McConnell and other senior Republicans in a bid to reassure them they don't have to support impeachment. "I've changed, I'm going to be good" was the implicit message.

There is also every reason to believe Trump's appeal to the extreme elements of his base, the far-right quagmire from which the rioters came, for peace and moderation ahead of the inauguration was sincere. The last thing Trump can afford right now is more violence in Washington or any of the state capitals where there is evidence violent protests are being planned. A replay of what we saw on our television screens last week would surely increase the number of Republican senators who would vote to impeach.

And, perhaps most significantly, there was the language the President used. Just as he didn't refer to the impeachment, he also didn't refer to the Republican Party. It was "no true supporters of mine" and "our movement" all the way.

Trump is a narcissist for whom the Republican Party was a means to an end. If, as a result of recent events, it turns its back on him he would have no compunction about going it alone with a Ross Perot-style presidential campaign in 2024 as an independent at the head of a far-right-wing political movement. And, even if he was barred from standing himself, there would be nothing stopping him from endorsing another candidate, someone probably hand-picked from within the Trump family circle.

This is almost certainly not the beginning of the end for Donald Trump; it is - as Churchill famously observed - "the end of the beginning". That is potentially a very scary thought.