In an
LA Times piece about the popularity of fantasy films, David Heyman speaks about the themes within Harry Potter, in particular its social issues.
Quote:
“I think the Potter films reflect, in some form, issues of loyalty and trust and friendship, and of propaganda and misinformation and people not being prepared to see what is before them, wanting to see only what they want to see.”
The article goes on to say that series' such as Narnia owe their success, on screen, to Harry Potter, which paved the way in terms of American audiences' reactions to casts from outside of the States.
Source:
The Leaky Cauldron