
I'd say it's the dichotomy between people who value order and stability at the expense of a few, and people who risk chaos for the betterment of the masses.

My favorite scene is from the first movie when Katniss is in the cave with Peeta and has to convince the audience, that she loves Peeta. It was interesting to see a character whose only motive is her family and survival interact with a character whose only motive is love a beauty.