Apparently the ACLU has an "online graphic novel" titled Defenders of Freedom up at their site. I find their use of wording interesting. The piece itself states, "We are not trying to disguise a civics lesson in a comic book" — though their tagline calls it their "first graphic novel" (apparently more will follow?).
This seems like another instance of "graphic novel" being used as an upscale synonym for "comics" — without regard for format (it's on the web!) — as opposed to using it to denote a separate categorical frame/artitic movement. The quote in the piece bears this out, since "comic book" is used fairly negatively here (and straight-up ties it to the notion of superheroes), when the work is obviously done in the "comic medium."
Here again a notion of a "visual language" would be useful. What the ACLU is trying to say (I think) is that they want to communicate this valuable information in a graphic form that is accessible (visual language), but they don't want it to have the stigma of "comics" (the social construct associated to superheroes, etc.) biasing people's opinions of it.