An underestimated divide in politics is between romantic crusaders and those who espouse more practical proposals. The romantics tend to be admired for their visionary boldness, and yet nearly always it is the practical politicians who are more courageous in the end.

Take the current fashionable theme of empowerment, giving power to the people. On one level there is no dispute around the issue at all. Every politician in the land is in favour of empowerment in the abstract. Imagine an election slogan that argued the opposite: "Take Power Away From The People!" It is hard to imagine voters giving the thumbs up to that.

The theme is similar to "Choice". When he was Chancellor I recall Gordon Brown pointing out to me at the height of his rows with Tony Blair on the subject: "Who is against 'choice'? It is like being against 'freedom'". Brown's issue with Blair was about the degree to which promising "choice" in schools and hospitals was illusory when there was no spare cash or political will to fund a surplus of places, the pre-requisite for genuine choice. Blair was promising "choice" when Britain had only begun the long climb towards funding levels in equivalent countries in Europe, a move from squalor to paradise in the space of around 10 minutes.

It was always a fantasy and the only option that arose was indeed a fantasy choice in certain parts of the country, where so-called diversity gave some schools the freedom to choose pupils. In recognising the limits Brown was being practical. Blair was being the romantic crusader, or to put it more prosaically, he was being impractical.

The former cabinet minister, James Purnell, is on the romantic wing too. Purnell has become one of the country's most stimulating politicians because he dares to surprise sometimes in a stifling, cautious political world where the unexpected does not happen very often.

At least I was surprised to see him pop up at rallies with Jon Cruddas, the Labour MP who is more recognisably on the left of the Labour party. I was also surprised by an article he wrote last month, much the best I have read from a Labour politician in setting the scene for a post-New Labour era. In the article he argued that the Blairite "third way" learnt the lessons of Labour's past mistakes, but elevated avoiding mistakes to an ideology. Purnell navigated a more daring third way, for example arguing: "What matters is what society can bear, not what the market can bear. If people cannot live on the minimum wage, then we need to change the market outcome."

Implicit in this analysis were some radical policies, although what they would be is not clear. That is why I place Purnell in the romantic category. The ideas are flowing now he is out of the cabinet, but if he were in the cabinet I am not sure what the precise policy agenda would be. Romantics never spend very much time in the cabinet. Another romantic, Alan Milburn, joined and left the government twice.

From the relative luxury of ministerial exile Purnell returns to the fray this week with a Demos pamphlet and accompanying articles arguing for "empowerment". In this case he comes up with a precise proposal to flesh out the theory. It relates to schools: "Real power would mean abolishing catchment areas and having pupils apply two to three years in advance. Over-subscribed schools could then expand or new providers start up. Conversely under-subscribed schools could be closed or taken over. Parents could be guaranteed one of their top choices."

The policy sounds great. I am not in favour of keeping useless schools in being by compelling parents to send their children to them. Who would be against allowing all the pupils to go to the best school around? Except that it would cease to be such a good school if it was so big that anyone who wanted to attend managed to do so. When the school became so big the hyperactive parents who view their children's education as an almost full-time activity would turn away. They would turn away even more rapidly if they clocked that nearly all the kids from the failing schools were heading for their chosen idyll. Meanwhile the head teacher who had been successful in establishing a good school would be so diverted in finding new buildings and appointing additional staff that he or she would no longer have the time to focus on what was happening in the suddenly expanding school. Elsewhere the failing school nearby fails further as resources are transferred to the once successful head teacher in order that he or she can buy up land and staff.

Empowering is more complex than it seems. A senior figure from a big charity tells me elderly people in care loathe the personal budgets thrust upon them as a form of empowerment. The charity has started to employ additional staff to help the supposedly empowered navigate their way through the jungle of apparent choices.

Romantics seem to be bold, but avoid the tough, more courageous route. Let us return to schools. Private schools are successful partly because of small class sizes. Similarly, state schools would be more successful if they had a teacher/pupil ratio closer to private education. That costs money. Winning a debate with voters about spending is difficult, but one left to the more practical politicians. The state has responsibilities to ensure standards are as high as possible. There is no debate about that. But as long as the state has such responsibilities it cannot detach itself entirely from outcomes of delivery. Unavoidably, accountability will never be with the so-called empowered users alone. Practical politicians who raise the money from taxpayers will want to know how the cash is being spent.

The practical politicians should also be getting on with addressing other more urgent needs, such as breaking up national pay bargaining, ensuring a supply of higher quality teachers, working out what to do with the trouble-making pupils that wreck schools, and establishing that best teachers are well rewarded and those who are no good can be sacked. These are the practical challenges. The romantics can sing along to John Lennon's most vacuous song and tell the voters what they want to hear: "Power To The People... right on."

s.richards@independent.co.uk