Joshua Partlow at the Washington Post has a great article about the role of a team of Spanish legal scholars in drafting the the constitutions of Bolivia, Ecuador, and Venezuela. One in particular, Roberto Viciano Pastor, is especially influential. They were influential enough, for example, that although Hugo Chávez initially wanted a bicameral legislature, they convinced him to go with unicameral.
I would love to see an article like this be expanded into a book. Constitution-writing is a black box, and it would be fascinating to know in more detail how it works. Obviously, the vast majority of the participants have no experience, so they need assistance. How are advisors selected? What do they do? How are the drafts worked out? This is particularly relevant with these constitutions, because they are so long and detailed. Interestingly, Viciano was publicly critical of the decision in Bolivia to accept some of the opposition's demands for revision:
"This is what those who call themselves revolutionary sometimes don't understand: In the revolution, you can't always reach consensus," Viciano said. "You either have revolution or you don't. But you can't force consensus."
Indeed, another question the article raises is what a constitution should actually do. For example, should it guarantee rights (let's say, health care) that the state simply cannot provide? There is a lot of fertile research ground for understanding the effects of a constitution on a population. Does its symbolic importance (such as empowerment) outweigh concerns about whether it can ever be fulfilled?