But it is hard to see how he can become leader again in this Parliament, in which so many of his own MPs refused to serve under him.
And that is a judgment for politicians to make, not for civil servants or for the Metropolitan Police.
A new study by Anthony Seldon of the office of Prime Minister gives too little credit to the many among its 55 holders whom he dismisses as failures.
A Prime Minister might, in the autumn, ask the Queen to prorogue Parliament until the day after exit is legally due on 31 October.
Bower writes him off as a loser, which is perhaps what he will end up being. But he did much better at the last general election than the commentariat expected.
I have lost count of the number of times I have heard its demise confidently predicted or stridently recommended. Houdini-like, it has so far escaped this awaited fate.
Behind his languid exterior lay a man of unusual principle, to whom all Conservatives have cause to be grateful.
It will then be time next weekend to dust ourselves down, and remember what truly unites us all.
Never before had British and Irish representatives put their names to a formal agreement of this kind as complete equals.