Cameron looks set to be remembered in history as the PM who chillaxed himself into oblivion. If he loses Scotland, he is finished, to be consigned to opprobrium and a legacy of failure, inability and uselessness. There will be substantial pressure on him to quit Number 10 even before the election - he will be like a bad smell, only worse. His Premiership since 2010 has been entirely wasted, frittered away in Portuguese fish markets and on Cornish beaches, and will be marked only by this one damning event. Cameron will be the PM who lost Scotland.
The enraging aspect of all this is that it is Whitehall's own goal. Those centralist control freaks are so constipated with power that it is their refusal to let go that is forcing the Scots to set off by themselves. If Cameron had pursued the Localism agenda that helped him to power, major constitutional reform for the UK along the lines of the Swiss federal model would have defused demands for schism. Instead of hitting the ground running in 2010, he couldn't wait to sink on the sofa with a bottle of Merlot and a Netflix release.
The grandees must already be quietly lunching to fund a runner with whom they can replace this stupid, complacent and lazy little man next year. Make no mistake, Cameron's head is on the block.