"But I'm a Cheerleader" exaggerates the whole premise so profusely that the illustration crosses the line from being merely satirical in an already much-satirized culture to being utterly dumb. The film's continually hyperbolic nature would be sufficiently offensive to bring protests from many, but for the fact that such objection would dignify the ridiculous and thus shed needless light on what amounts to nothing more than sheer silliness.
Megan (Natasha Lyonne), the captain of her high school's cheerleading squad, is, on the surface, a girl as spunky and typical as one might imagine. Her parents love her, and she's obsessed with her boyfriend. However, Megan has a secret that she hasn't yet come to grips with: she's a lesbian. She thinks of fellow cheerleaders when she kisses her boyfriend; rather than loosely-clad guys, her posters show well-endowed women and her mind wanders into territory when she sees her mates with nothing on.
In reality, Megan seems to be the only one who's not in on her little secret. Imagine her surprise when one morning her family and friends confront her and not only explain that they understand her sexual preference better than her because they have noticed her posters of Melissa Etheridge but that they are sending her to a costly, yet highly reputable, program called True Directions to stray.
True Directions is somewhat similar to the fictional mental institutions of Hollywood in that it sends a person to your house to pick you up, houses its inhabitants in dorm-like buildings with little supervision, and features Clea DuVall as its most beautiful female resident (Georgina from "Girl, Interrupted"). You can tell right off the bat, like many Hollywood loony-bins, that the location is full of phonies. RuPaul plays Mike, the head male advisor (actually, the only male counsellor from what we gather) out of drag. Mike wears a shirt declaring "Straight is Great" drives a pink van and goes through all of the stereotypical movements at one point or another. Yet, Mike maintains that, while our suspicions say otherwise, he is "an ex-gay". When he gawks at another male, those suspicions are confirmed.
Mike is, of course, merely an indication of the message of the filmmaker: you are what you are, and nothing can change that. Megan is a lesbian, whether it is irrelevant by genetic predisposition or preference - she will remain a lesbian at heart no matter how much "True Directions" propaganda preaches through her ears.
A set of clichés as old as pompoms and absurd as Will Ferrell and Cheri Oteri's Spartan Spirit cheerleaders are performed in the last few scenes of "But I'm a Cheerleader". The cast may have joined arms, formed a chorus line and pumped out a version of "Springtime for Hitler" given the ludicrous existence of the previous 80-some-odd minutes of the film, and I doubt anyone would be shocked.