What is in his control is his speech to Labour’s conference, which his colleagues are billing as the most important speech of his life.
It will be autobiographical, personal they say, and his chance to belatedly connect with voters, to bury once-and-for-all the widely held canard that Etonian Johnson is the man of the people and that he - as the working-class knight - is the embodiment of privilege.
“This will be Keir like you’ve never seen him” said one.
The mind boggles.
He and his colleagues will hope that the speech has more impact than his 12,000 word profession of socialist faith, “The Road Ahead”, which - as I said after it was published - you could imagine being authored by Johnson (except for the promise to transfer power to trade unions, and the absence of corny jokes).
I’ve not met anyone here at conference who thought it provides a compelling reason for wavering Tories or - more importantly - those on low incomes who can’t be bothered to vote at all as to why they should vote Labour.
Paradoxically, Johnson may provide that reason in the coming few days, if he doesn’t belatedly reverse the decision to axe the £20-a-week universal credit uplift.
If the prime minister presses ahead, at a time when energy and food price rises are crippling the living standards of those on lower incomes, Starmer’s message to voters for months to come will be a simple resonant one: “Johnson hurts the poor and rewards his wealthy friends”.
The lamentable economic outlook for those on middle-to-low incomes means that charge against the government is likely to stick.
Which of course creates an awful dilemma for Starmer and his team. For the good of the country, they hope Johnson reverses the UC cut.
For the good of their party, they are praying he doesn’t.