The New Mutants: Superheroes and the Radical Imagination of American Comics (Postmillennial Pop, 1)

You're getting a lot of good answers. I second the God Loves, Man Kills recommendation, it's X-Men at its most explicitly political. And it's short, just one graphic novel. Depending on how far you go with it, these could be good resources (though it would probably make sense to read more X-Men first): Comics in Focus: Chris Claremont's X-Men (documentary) The Claremont Run: Subverting Gender in the X-Men - J. Andrew Deman The New Mutants: Superheroes and the Radical Imagination of American Comics - Ramzi Fawaz