The Constitution did not create it. As Anderson notes, people sometimes forget that all institutions are human creations. Anderson argues that globalization is the driving force behind the emergence of post-modernism. The world's cultures are on display like never before. The entire world can watch what happened in Tiananmen Square.
Terrorists operate in a global theater.
The entire world gets a glimpse of Hollywood culture through the OJ Simpson trial. With all these SCRs around, it's hard to argue that one is the Truth, although the Pope and religious fundamentalists in Iran, to name two, still try. Thus, post-modernism spreads. Anderson doesn't go this far, although he notes that others do believe this. However, given any set of information, a person can create several different stories.