Firstly, just about all of these polls employ arcane methodologies that weight everything in Labour's favour. In other words, even when the Tories are bouncing back, as they seem to be now, there has to be a powerful suspicion that the reality is that Labour were never anywhere near them in the first place; that the polls themselves were entirely misleading, insofar as they painted a picture of, at one point (laughably), the possibility of Brown actually forming the next government, somehow. And they still are misleading, in that they are suggesting that the Tories are recovering in some way, when, in fact, all they are doing is further consolidating and increasing their lead. I reckon you can add another five points onto the Tories' lead in this ICM poll. That would bring it into line with the only pollsters I trust: Angus Reid (who recently put the Tory lead at 14 points).
In addition to this is the fact that Cameron has had a tremendously good couple of weeks. You can say whatever you like about the Ashcroft thing, which appears to have exercised the minds of some of the bigger bloggers, like Guido, but to ordinary people I guarantee that this non-issue isn't even on the radar. I felt, and others I have spoken to (at least, those few who were interested) felt that Cameron handled it pretty well. Take the thing away altogether, and you are left with Cameron's excellent performance at his party's spring conference and his confident, crystalising and increasingly positive message about the appalling state of the nation, Brown-Labour's legacy, and what he's going do about it. In contrast, Brown has been, well, just Brown. Lying to the Chilcott enquiry, talking more nonsense about the debt crisis (1) and the economy he destroyed and now playing party politics once again with our armed forces with yet another unwanted, unwarranted trip to Afghanistan.
People are not stupid. They see that Brown is desperate and will, as John Major is apparently about to say, try anything to stay in power. On the other hand, they look at Cameron and they see a leader who is finding his voice - and preparing for office. These dodgy polls might reflect the direction of public opinion, therefore, but, because they are so flawed, they certainly can't be trusted to provide accurate figures for the actual state of the electorate's voting intentions. I therefore maintain that whatever the polls say, Labour are about to get the biggest electoral kicking of their lives, and deservedly so. And, as I also said before, I've put my money where my mouth is.
Finally, it's worth offering a final piece of evidence that Cameron really is getting into his stride (or, to please the doom-mongers, but obviously not his detractors, 'bouncing back'). His speech today to the Welsh Conservatives in
(1) Prodicus is excellent on this particular Brownian nightmare this evening. Worth the read.