Oliver Kamm makes two good points here:
Tony Blair came about because Labour had failed, electorally and philosophically. He has made Labour successful, but been notably poor at expounding his broader achievements.
He's right that Blair has been poor at expounding his achievements. The best measure of this was Labour's support at the 2005 general election. It got 9.6 million votes. That's a loss of 3.9 million since 1997 - equivalent to the entire electorate of Scotland. And it's 1.9 million less than Labour got in 1979. But even Blair's worst critics would have to concede that, Iraq apart, the 1997-2005 government was much less bad than the 1974-79 one.
Oliver's second good point is that Old Labour failed. One of Blair's errors has been to misrepresent this point. He's pretended that New Labour has been a necessary response to new times, globalization and modernity - just as Brown claims to offer a "new leadership for this new time."
But this is false. The real reason why there had to be a "New" Labour is that the old Labour project was a disaster. It was just impossible to provide sustained full employment without creating inflation and a profit squeeze. Labour had therefore to rethink its economic philosophy.
In failing to state this case Blair has given the impression that he has betrayed a noble tradition. In fact, that tradition had to be abandoned. Old-style social democracy was economically infeasible.
In this respect, the idea that New Labour is "all spin and no substance" is 100% wrong. New Labour is a substantive economic programme, with much to be said for it.
I expound on this at great length you know where.
Here, though, I'm harsher on Blair than Oliver. In failing to make this case properly, and in giving free rein to the verminous Alistair Campbell, Blair has degraded political discourse.
It is, surely, a damning indictment of Blair's years in office that he has made it possible for Michael Howard to make a good point.