There is an excellent piece on the Ashcroft affair from Martin Ivens in the Sunday Times today. He quotes a member of Team Cameron: "Why didn't David just take Ashcroft out and shoot him? His work is done. What's the point of him hanging about?" Well said.
No one has quite got to the bottom of why the Tory lead has shrunk. But one reason might be the sense that David Cameron is not quite as decisive as he ideally should be.
He lost his nerve over George Osborne when he became an embarrassment in Corfu and he seems to have lost it again over Ashcroft.
Cameron has modelled his rise on Tony Blair but has never shown Blair's brutal approach to his own party. This is why the base of the party remains unreformed. His A-list had to be seriously watered down after he found local parties unreceptive to black, Asian and woman candidates. Baroness Warsi was eloquent on this subject before she was found a place in the House of Lords and hence the Tory front bench.
It will be interesting to see whether David Cameron's first act of serious ruthlessness will coincide with a recovery in the polls.