I agree that a major shift in public opinion has occurred but I think it happened some time ago, partygate did it and I thought then that it was a position that it was always going to be hard to recover from, the switch it collective minds had been flicked. What Truss has done is send public opinion into a cataclysmic nose-dive. Sunak really can't turn that around, the only question is when will the Tories lose a General Election rather if they'll lose.
Sunak is already making major mistakes with the appointment of Braverman and it's becoming rather untenable and rather quickly. He told us it was a minor breach that she reported herself. That appears to be, from multiple sources, a complete crock of shit.
Imagine if he's forced to get rid of her so soon into his premiership, it can only reflect badly on his decision making ability and yet again opens up the lying to parliament question, which he'll brush aside with "it was true to the best of my knowledge" but in the minds of the people, that won't wash any more
William Hague was partly right about the death spiral, where he was wrong was the assumption that Sunak (or someone other than Johnson) could fix it, they can't