Bryan Singer turned down the chance to direct the first X-Men film multiple times before the producers hooked him with the idea of mutants as an oppressed minority. The analogy enticed both Singer and Ian McKellen two gay men because they had first-hand experience with being hated and mistrusted by the general populace. It's a concept that's been baked into X-Men from the start, with the Civil Rights struggle also considered analogous to the mutant struggle. What you might not know is that multiple lines of dialogue in the original film are actual, real-life quotations from figures like Civil Rights activist Malcolm X and Communist witch hunter Joseph McCarthy. Oh, and Senator Kelly questioning whether they should teach about mutants at school? That's less fiction and more a refernce to the real, horrible Section 28, which tried to ban the teaching of homosexuality on the curriculum which Ian McKellen successfully campaigned against.
Tom Baker is the Comics Editor at WhatCulture! He's heard all the Doctor Who jokes, but not many about Randall and Hopkirk. He also blogs at http://communibearsilostate.wordpress.com/