The constitution is so enduring, in part, because it's so short. Most countries seem to view their constitutions as the supreme legal code, and write the document as though it were to be the clear cut arbiter of every argument. The U.S. document lays out a skeletal structure of government, a few goals and principles, and a minimal number of managing directives. It is then up to each age to fit its new set of problems against that short script, with the help of constitutional courts.

The constitution works, and lasts, because it is flexible, and allows government to evolve in line with the evolution of the problems of government.