As I wrote in the Sunday Telegraph at the weekend, Damian McBride's vile emails sent from a Government address and the heavyhanded arrest of Damian Green both reflect a dangerous belief that the public interest and party political interest are identical, co-terminous.
Last night, Labour insiders made little attempt to pretend that the logic behind the 50p tax was fiscal: they know full well that it will raise next to nothing. But they welcome it with glee as a cunning plan to unsettle the Tories and throw a big red spanner in the Cameroon works.
Tax is justified as the necessary membership fee of a civilized society: it pays for the defence of the realm, basic infrastructure, public services and the welfare of the needy. Wise politicians understand that there is a solemn and fragile covenant between taxpayers and Government. It is the task of the State to persuade the taxpayer that his confiscated earnings are being spent well, respectfully and providing value for money. There was a time when the Brownites spoke grandly of 'progressive universalism': the core principle that all taxpayers must benefit and feel that they benefit from the way in which their taxes are spent.
From the English civil war to the poll tax, those who have forgotten this covenant have paid a grievous price. The 50p tax may indeed make life difficult for Cameron. But that is a deplorably shoddy basis for a tax increase: and, yet again, a grim reminder that this discredited gang have completely forgotten that the State is not a convenient tool to advance party political interest. They will be reminded of the difference soon enough - and it will be painful awakening.