However much the schooling decisions of Tony Blair and Harriet Harman have torn apart the Labour party, they have also performed an essential service for their colleagues in forcing them to face up to what ordinary parents really want for their children. Most parents - as party leader Blair knows - will move heaven and earth to get their 11-year-olds into the best school in the neighbourhood, whatever its status. If they support their local comprehensive, it is because it offers them what they want, not because they have been directed there for the greater good. And we are not just talking about the middle classes here.
With a schooling system now succumbing wholesale to choice, diversity and selection, Labour faces an acute dilemma. Having eagerly embraced standards, choice, specialism and diversity as its own, the party now has to reconcile all these aspirations with its long-standing commitment to the comprehensive ideal and its renewed rejection of selection.
Not surprisingly perhaps, there are various bits of policy which do not add up. Is parental choice (or diversity for that matter) compatible with renewed local education authority control of admission systems? And how can choice and diversity be squared with controlled intake to comprehensives?
As Mr Blair and his education spokesman have acknowledged, there can be no going back to the old days of LEA direction or banding. Now David Blunkett admits that, while the left of the party has been afraid to debate either structure or selection, he has had no choice. First, in the wake of the Blairs' choice of a grant-maintained school for their son, came last year's policy paper, Diversity and Excellence, which skilfully avoided either abolishing GM schools or handing them back to the LEAs by compromising on a new category of foundation schools. Then, after the Harman selection row, "Tony Blair and I have decided to debate it openly". Blair proposed fast-tracking in his next speech. And this week Mr Blunkett launched the idea of diversity within comprehensives, alongside a sharp attack on drab old dogma like mixed-ability teaching and uniformity, This new brutal frankness within the Labour party on the failures as well as the successes of comprehensive schools has to be welcomed. There is plenty of evidence that the good comprehensive school, with a well-balanced ability intake, scores in examinations and with parents, but that a secondary modern masquerading as a comprehensive fools no one.
So Mr Blunkett is at least partly right when he says that the comprehensive system has to work in a wholly new way if it is to succeed in the future, and certainly right to open up the debate. Too many of the comprehensive school's most passionate supporters are still looking back to the original golden ideal, without taking too much account of the practical difficulties in the way of its achievement, or accepting that a Labour government will have to start from where we are now.
The next question is how well the beguiling new Blunkett scenario might work in practice, and here the habitual scepticism of teachers and their unions is already evident. Although he has already outlined a more universal and user-friendly version of fast-tracking than his leader, either version demands a well-managed school. As developed by Mr Blunkett, fast-tracking does not mean skipping between year-groups, but it does extend to stretching every child, whether they have special needs, average ability, or fast-tracking potential. Hard to fault it as an ideal, harder to guarantee, although Labour is building up its list of case-studies.
This week's big idea - diversity within the comprehensive rather than within the system - is another interesting piece of lateral thinking which would demand a major effort of co-operation and imagination from schools. Rightly suspecting that the specialist school (an idea espoused by Labour) can be another name for selection, Blunkett now proposes that children should have access to specialist subjects at any comprehensive of their choice, either through the wonders of technology, or through grouped "families" of schools sharing their expertise. Independent schools might be included, but obviously sharing would be easier in urban areas.
It is an idea inspired partly by American guru Howard Gardiner, who developed his theme of different sorts of intelligence matched by different specialisms within the school at last year's North of England conference. And, like so many Labour blueprints, it is already working in Birmingham.
Teachers in the audience at Mr Blunkett's Social Market Foundation lecture were doubtful whether it would work everywhere else. There is little incentive for schools to co-operate in a competitive climate, and funding shared courses could be difficult. It is certainly true that experience of failed sixth-form consortia has shown how difficult schools find it to co-operate on joint timetabling and shared teachers. And is it the children who have to travel or the specialist teacher? All these tiresome details get in the way of brave new visions.
Of course the details are important, as critics of Labour's policy documents regularly point out, but the visions matter too. It is not just to woo the middle-class vote that Labour needs to open up a fresh debate on comprehensives and selection and be honest about what went wrong. In a system increasingly skewed towards the needs of the selected few, rather than the majority, we need fairer solutions plus the high standards that all parents want, and that will inevitably mean hard work for teachers, as well as for politicians.