Yet, out of this reasonable set of proposals, the Eurosceptics invent the most fanciful set of horrors.
They claim it involves transferring vast new responsibilities from national to European level. But, unlike previous treaties, the text does not envisage any significant expansion in the EU's field of competence. The EU will remain a union of member states who themselves determine its powers and responsibilities.
There will be no change in the nature of the European Commission. Its job will still be to make proposals and carry out what is agreed - it is not to become an all-powerful central government.
The Eurosceptics claim that the term "constitution" implies that the EU is a state. But Britain is a member of the International Labour Organisation that has a constitution, without anyone ever thinking that the ILO is a state. Even sports clubs have constitutions. The term simply means "rulebook".
They claim that the 30-month chair of the European council amounts to an unelected president of Europe, although the job description specifies that (s)he is chosen by the prime ministers to prepare and chair their meetings, with no autonomous decision-taking power.
They even object to long-standing features of the EU, such as the fact that EU law supersedes national law. This has always been the case: countries should carry out what they agree in the EU, the very principle we relied on to win our case against France on their refusal to accept British beef. Or do the Eurosceptics actually want a country to be able to agree one thing at EU level and then do the opposite at domestic level?
In order to widen their appeal, some Eurosceptics are now avoiding criticising the draft, simply calling for a referendum on it. The no campaign on the euro has re-invented itself as Vote 2004, trying to hide its Eurosceptic agenda.
To hold a referendum would be a major change to our own constitution, as Britain has never ever ratified an international treaty by means of a referendum. Instead, parliament carefully scrutinises treaties in every detail before ratification. That's what has happened with all European treaties since we joined, including the most significant one by far - the Maastricht Treaty. Many of those now calling for a referendum (including Michael Howard, Michael Ancram, David Davis, and convention member David Heathcoate-Amory) opposed a referendum on Maastricht, although it was a major increase in the EU's field of responsibility, unlike the present draft constitution.