In his review of The Dark Knight (four stars -- who'da thunk it?), Roger Ebert notes that a certain supporting character in the movie takes a stance that "has current political implications."
No fooling. The grander themes at work in The Dark Knight revolve around universal concepts about what makes society tick (or explode), but there is one brief allusion that should be cited in the upcoming presidential debates, and it involves the issue of wiretapping.
It's hard to say whether or not the Nolan brothers thought this one through when they devised the screenplay, since we're talking about a relatively small component of the plot here, but it's still far more overt than, say, "Only a Sith deals in absolutes."
It comes back to this idea of Batman as this crazed fundamentalist, an angle the movie approaches but never quite realizes, probably because many audiences would have a hard time with it if the character were difficult to empathize with. It's another reminder why Frank Miller's The Dark Knight Returns offers the best Batman story ever told: He makes Superman look like a wuss.