Categorism as a Phobia

It's usually not very funny when a character reeks of prejudice, bigotry, discrimination and so on against a certain category of people. The phenomenon is called racism when it's against a race or ethnic group, homophobia when it's against homosexuals, and so on... but wait a moment! The word "homophobia" has "phobia" as part of the word! Let's just roll with that, and portray homophobia as if it was an actual clinical phobia. Hilarity Ensues as the character runs around full of irrational fear of homosexuals, heterosexuals, Muslims, Christians, transgender people or whatever category of people.

When Played for Drama rather than Played for Laughs, deaths and ruined lives are more likely than hilarity to ensue, and mental problems and bigotry get mixed into something deeply disturbing.

While this trope can be used on any category of people, it's always easiest when it's a category where a pretty established word for categorism against it ends in the suffix "-phobia": Homophobia against homosexuals, Heterophobia against heterosexuals, Islamophobia against Muslims, and so on. Sure, these words don't indicate a real phobia any more than the word "mouse-pad" indicates a pad made of mice, by mice or for mice: it's a matter of etymology, not a matter of real meaning. Still, the words having "phobia" in them open up for some fancy wordplay and may also help preserve the Willing Suspension of Disbelief. This goes both ways: a Noble Bigot or similar who regard homosexuals as lesser people who should be second class citizens could get the defense that he couldn't possibly be homophobic - after all, he's not afraid of gay people.

See also The Mentally Disturbed and Hollywood Personality Disorders. Compare Black and White Insanity and Troubled Sympathetic Bigot. Compare Internalized Categorism and Sex Is Evil and I Am Horny, where the character has an aversion against himself because of his idea about what it mean to belong to a certain category or have certain desires.

Comic Books

 * In Bitchy Bitch Midge has a crazy coworker who usually is merely bigoted. But in one episode she developed some weird panic anxiety against a temporary coworker because she believed her to be a pagan. The boss had to waste a lot of energy keeping her reasonably sane.
 * Bitchy Butch is portrayed as suffering from severe heterophobia to the point that she can hardly take a walk outdoors because she freak out over seeing people being openly heterosexual.
 * Pondus excels at this. He doesn't seem to have much real bigotry or even prejudice, it's just that he has this crippling fear of homosexuals and homosexual sex acts. He has nightmares about making out with guys, he starts shivering with fear at the sight of real life gays, and so on.
 * At one point, his friend Jokke felt like messing a bit with him. So Jokke asked him if he had ever masturbated, and of course Pondus said yes. Jokke then proceeded to inform Pondus that Pondus had actually had sex with a man: himself. In the next panel, Pondus is screaming psychotically while washing his right hand, and Jokke is laughing.
 * This comes to a head when Pondus gets a gay married couple as neighbours. The pair are perfectly nice, if extremely flamboyant, and Pondus is perfectly capable of getting along with them (barring some slight snarking)... Unless they start alluding to actual homosexual acts, at which point Pondus shuts down mentally and runs away screaming or goes for the Brain Bleach.

Film

 * Borat went into an over-the-top panic attack when the B&B he was staying at turned out to be operated by a Jewish couple.

Literature

 * Dynamisk Psykiatri ("Dynamic Psychiatry") by Professor Johan Cullberg is one of the main psychiatrical textbooks in Sweden. Earlier editions contain advice on how to "cure" homosexuality, even long after international psychiatry had abandoned the idea of considering homosexuality to be a mental disturbance. The 2003 edition has abandoned the talk about curing homosexuality, instead talking about how to cure homophobia. Treating it as if that was a real psychiatric disorder. Needless to say, this textbook is subject to much critique and protest.
 * Completely averted in DSM-IV, the international psychiatry's Diagnostic and Statistical Manual of mental disorders.

Live Action TV

 * In one episode of Law and Order SVU, the villain of the week had killed a lot of immigrant children. The killer was overtly racist with his serial killing being an obvious hate-crime. But the defender somehow managed to convince the jury that the man couldn't help it - that his racism should be regarded as a mental problem.

Real Life

 * the now-defunct Gay Panic defence for hatecrimes.