A cynic might be tempted to say that when politicians run out of ideas, they turn to making or changing the constitution. Take the European Union. Its last big project was the single market as conceived by Jacques Delors, the European Commission's then-President. That project has still not been completed, but the missing bits are a continuing process, not a new idea.
Since then, the EU has tried a little of this and a little of that: a little common economic policy around the introduction of the Euro, a little common foreign policy around the Iraq war. None of it has been very successful. Indeed, none of it has an advocate of the stature of Delors.
So the EU turned to constitution making. It set up a Convention, which produced a draft treaty, and soon an Intergovernmental Conference will try to take the project to a conclusion.