Some people think that "A" level exams are now so easy that an "A" grade is almost without value.
Some people think that office workers should be allowed to stand on a chair to change a light bulb without getting a mate to hold the chair steady first.
Some people think that, in our zeal to protect children from child molesters, we have started to check the criminal records of people whose criminal records don't really need to be checked.
Any one of those things might be true; but it is hard to see what each of them has in common, and what any one of them has to do with the belief that "gay" is a more polite word than "pooftah". Yet they are all routinely brought under the all embracing umbrella of Political Correctness. Kids aren't allowed to fail...elf and safety won't let you do anything...all adults are assumed to be paedophiles...It's Political Correctness Gone Mad.
This is, I think, a relatively new development. When the right first discovered Political Correctness -- in the 1980s -- they didn't really want it to mean much more than "hypersensitivity", especially, hypersensitivity about race. It might be okay to insist that we say "black person" rather than "nigger". It might even be okay to ask us to avoid using "black" in contexts like "accident black spot" or "black day for this country". But to tell us to call blackboards "chalkboards" and blacksmiths "smiths" -- well, that was Political Correctness. But they've more recently decided that anything from putting frosted glass in swimming pool windows to asking Christmas grottos to conform with fire-regulations are examples of Political Correctness Gone Mad.
So: what are the kinds of people who talk about Political Correctness talking about when they talk about Political Correctness? A rummage around the interweb has left me none the wiser. Mr Google first directed me to a website called Political Correctness: The Awful Truth which lists 25 areas in which Political Correctness has "replaced "British politics".
For example: In 2004 a football coach was censured for calling a player a "fucking lazy nigger".  This was an example of Political Correctness, because (we are assured) the coach would not have been in trouble if he had called the man a "fucking lazy bastard" or a "fucking lazy wanker" -- even though this would have been equally rude.
Mr The Awful Truth thinks it is quite obvious to everyone that some races really do have inherent characteristics: Jews really do like to work in finance, Asians really do like to open corner shops, Chinese really do like to run take-aways. It is only Political Correctness that stops us from saying so. Because obviously, no-one does ever say that Chinese Take-Aways are often run by Chinese families. Only renegades like Mr The Awful Truth dare point this kind of thing out.
He rehearses some standard arguments for thinking that the prohibition of fox hunting was a bad idea: the fact that it was implemented anyway proves that Political Correctness had "made an ass of common sense".
It is obvious, he says, that children nowadays are allowed to do whatever they like -- just go to any supermarket and observe the state of anarchy there -- and it is equally obvious that this is the fault of "PC legislation" against smacking and caning. "I can only assume that the government is going all out for 100% anarchy in the classroom. The consequences for society will now be dire. Anyone with an ounce of common sense can see that." 
He concedes that slavery was a Bad Thing, but adds:
"So what I can't understand is why the PC Brigade is making so much fuss about something that happened hundreds of years ago and no one who was involved with it (on either side) is alive today. So who should apologise and to whom and why?...
If we are into apologies for past atrocities, why don't they call on Germany to apologise for two world wars and the slaughter of six million jews? Many of the people involved on both sides are still alive today."
Because Germans are well known for not having any guilt about their Nazi past. And there has been no movement to arrest and punish former Nazis.
Now, you might want to argue in favour of any of these points. Maybe "nigger" can be used as "low abuse" without actually implying that the speaker is racist -- in the same way that "wanker" can be used as low abuse without us inferring anything about the speaker's views on self-manipulation. Maybe you think that retrospective apologies for the slave trade are a bit daft and that it's pretty silly to stop half a dozen rich dudes from chasing foxes through the countryside but allow farmers to keep chickens in horribly cramped conditions. I'd be prepared to defend anyone one of Mr The Awful Truth's positions, apart from the one about inherent racial characteristics. 
But what do they all have in common? In what ways are they all examples of a thing called Political Correctness. Fortunately, Mr The Awful Truth tells us:
"the term Political Correctness includes:
1) Doing the reverse of what common sense would suggest
2) Inconveniencing the innocent while making life easier for the wrong do-er
3) Not telling the truth in case it offends
4) Changing the language where you perceive it may offend
5) Doing exactly the opposite of what you preach
6) What you do has the effect of making the problem you were trying to cure far worse
7) Doing ridiculous things just for a political reason
8) Favouring a minority just for a political reason"
Or, in short: Political Correctness is anything which I personally don't agree with.
This doesn't help very much. But hold on to point 1, "common sense". We may come back to it.
Another website, called Our Civilisation is a little bit more helpful. Although it is couched in comically over-the-top rhetoric ("PC is a communal tyranny that erupted in the 1980s" "Political Correctness is a social dementia") it starts out with a perfectly coherent definition. Political Correctness is about limiting freedom of speech. It claims to be about the avoidance of offence, but in fact, no-one has any right not to be offended. At one point, the writer Mr Civilisation seems to be veering to an actual definition: that Political Correctness is the idea that behaviour which was previously a matter of social convention became a matter of law. We used to say "If you say 'nigger' everyone will think you are an idiot and not want to be your friend" but we now say "If you say 'nigger' you will taken to court and fined."
Political Correctness, according to Mr Civilisation holds that "particular ideas, expressions and behaviour, which were then legal, should be forbidden by law, and people who transgressed should be punished." It's very doubtful if Political Correctness of this kind has ever existed: it is very doubtful that there has ever been a legal requirement backed up with legal sanctions that you should say "woman" rather than "lady" or "visually impaired" rather than "blind" or that anyone ever said there should be. But if there had been they would have been examples of Political Correctness.
This is quite helpful. As a matter of fact, there is no such thing as a horse with an ivory horn on its forehead. But if there was, it would be called a unicorn: we know what we are talking about when we talk about unicorns, and if we ever saw one, we would recognise it.
The best Mr Civilisation can come up with is a law from Canada which makes it a crime to advocate genocide and another which makes it a crime to "wilfully promote hatred against an identifiable group" ("except in private conversation"). Which rather implies that he thinks that before the social dementia set in, it would have been okay for me to make a public speech stirring up hatred against Ruritanians -- even to stand up and say "I think that we should wipe out all Ruritanians from the face of the earth". Saying that this is no longer okay seems to be a very mild form of social tyranny.
He has, in fact, a very strange theory that since our parents did, in fact, use terms like "nigger", "poof" and "coon" our declaration that such words are not acceptable amounts to a rejection of the values of the generation which won the Second World War. Political Correctness is nothing more than an act of infantile rebellion, in which we deliberately "revere" the people and value that our parents despised, go against tradition, etc etc etc
This slippage seems to happen rather a lot among people who believe in the International Political Correctness Conspiracy. It is never quite clear whether they think that while it may be offensive to call a gay man a poof, it shouldn't be illegal to do so; or that it isn't offensive to call a gay man a poof because the term isn't really all that insulting; or that it doesn't matter if the term is insulting because common sense (i.e my unexamined assumptions) tell me that I ought to hold gay men in contempt. Another version, particularly prevalent in the Nasty Mail, is to say that it may or may not be offensive to call a gay man a poof, but that no-one complains when gay men call straight men -- I don't know --"breeders" or something -- which shows that gay men have got the real power and straight people are the oppressed minority. And that it gives you cancer.
Finally, the disturbing Campaign Against Political Correctness -- the one initially set up by Laura Midgely and her husband to prevent homosexual frogs being given the same rights as heterosexual frogs -- appears to use the term Political Correctness primarily to mean "anti-racist legislation". In its section about "ridiculous" examples of Political Correctness it cites all the usual suspects: bakers shops selling "gingerbread people"; prison officers being asked to call inmates "Mr"; changes to the text of Enid Blyton's books.  But the examples of "dangerous" Political Correctness it cites are mainly examples of "positive discrimination" or "affirmative action" -- local councils trying to encourage black people to become police officers or fire fighters, or as the stories put it, "banning white people".
Many of these stories are drawn from the pages of the Nasty Mail and the Nasty Express. Some of them can be very easily debunked: the idea that anyone banned the display of England flags during the World Cup is just. not. true. Many of them contain quotes from concerned citizens. Well, from two concerned citizens, at least.
John Midgely of the Campaign for Politcal Correctness said "What is the world coming to when you are not allowed to put a bit of chocolate sauce on a cone."
John Midgley, co-founder of the Campaign Against Political Correctness, condemned the plans, saying people should be "proud to celebrate" Guy Fawkes night. "This idea is from the same school of thought that says you can't celebrate Christmas or call a chairman 'a chairman'. It undermines our traditions and way of life," he said." 
Laura Midgley, of the Campaign Against Political Correctness, added: "It is totally ridiculous political correctness, nobody wants to talk about gingerbread people. They are what they are. It is not just an innocent mistake. Whoever did it, I hope they will think long and hard about it. If these sorts of things go unchallenged, they become the norm." 
It would be very interesting to know what relationship the Campaign Against Political Correctness has with these newspapers. Do the Express phone up the Midgleys for a quote whenever they find a sensational breaking story about someone's biscuits being the wrong shape? Or do, perchance, some of these stories originate in press-releases that the CAPC has sent to the papers?
The site reproduces an essay by John Midgley which -- apart from one apocryphal reference to "person hole covers" -- is a rant against the McPherson report into institutional racism in the police force. Amongst the colourful metaphors ("According to the Commission for Racial Equality, there must be an all singing, all dancing plan that stretches like the tentacles of an octopus into all of the other plans, strategies and visions that the law dictates that your school must have") the claim seems to be that McPherson involved the police, and therefore other institutions, in a lot of un-necessary paper-work and form-filling. For all I know this might be true. But where is the connection between "When the government tried to tackle institutional racism in the police force, they went about it in an unnecessarily bureaucratic way" and "I read in the Nasty Express that some bakers shops now sell biscuits called Gingerbread People"?
The website includes a breathtakingly nasty cartoon which suggests that qualified people are sometimes turned down for jobs because they are white, and "that this is a legal kind of racism, introduced by the politically correct, kind of like what existed during the Nazi era."
Kind of like what existed during the Nazi era.
 Not that anyone did try to stop us using terms like "black spot". Or if they did, they didn't try very hard. The 1992 currency crash is universally referred to as Black Wednesday; the day after Thanksgiving is commonly called Black Friday.
 He actually called him a "thick, lazy nigger", but one can't worry too much about facts when reading about conspiracy theories.
 Smacking has not been banned, although some people think that it should be. It is literally true that the last government removed the defence of "reasonable chastisement" when a parent was accused of cruelty, but this does not mean that it is now illegal to chastise your child reasonably. It means that the law itself now defines what is reasonable and what is unreasonable whereas it used to be decided by juries on a case-by-case basis. So if Mr The Awful Truth is right, then the problem is not that parents aren't allowed to hit their children, but that they aren't allowed to hit their children hard enough. What the law now bans is hitting with sticks, hitting hard enough to leave cuts and bruises, etc.
 It might possibly be that first and second generation immigrants are more likely to work in family businesses than people who have lived here for longer, but that doesn't imply a genetic link between the Indian sub-continent and retail. What percentage of Pakistanis do work in retail? What percentage of corner shops are run by Pakistanis? Are we dealing here with actual data, or merely with "common sense" (i.e my unexamined assumptions)?
It seems perfectly sensible to remove unintentional double entendres from books which are going to be read out loud to children: what possible sinister political purpose is served by saying that the diminutives of Frances and Richard had better be Franny and Rick, as opposed to, er, Fanny and Dick? It is interesting to consider that if a modern day Mrs Whitehouse suggested that the lyrics of My Ding-A-Ling" sounded a bit rude or if a modern day Dr Bowdler produced an edition of Shakespeare that omitted the passages that a respectable father wouldn't want to read out in front of his children, they would be regarded, not as slightly silly old fashioned prudes, but as dangerous members of the Political Correctness Brigade bent on destroying the very cock jokes that made this country what it was today.
 Need it be said that the "now Bonfire night is banned" story was about one council which had decided to let off fireworks on Nov 5th, but not to have an actual bonfire? (Does anyone have a bonfire on Nov 5th? When we were kids, we called it "Firework Night".) This was partly due to health and safety concerns, and partly because bonfires are bad for the council's carbon footprint. The suggestion that it had something to do with not offending minorities seems to be pure spin.
 This is actually worth unpacking a bit. We used to say "policeman": we started to say "police person" because women as well as men can work for the police. We used to say "chairman"; we started to say "chair person" because women as well as men can run meetings. People then started to joke that we would have to say "Personchester": this is funny because the name "Manchester" comes from the Latin "Mamucium" and has nothing to do with men or women. It's a comic example of hyper-correction. Amusing hyper-correction may occasionally happen: there is a story that a US police force found itself referring to a road as an "Accident African-American Spot" or (even better) that someone described Nelson Mandela as "the first African-American president of South Africa." Anyone, then, might laugh at a Gingerbread Person: the sensible rule that you should say "fire-person" and "post-person" has been comically applied to a biscuit. However the Common Sense Brigade think that it's very serious -- not an innocent mistkae, but that sort of thing which must not be allowed to become the norm. And they think that calling a chairman a "chair" or a "chairperson" undermines our way of life. Its the use of gender-netural language in general -- not this particularly silly example of it -- which is dangerous. The life-changing joke about gay frogs is in the same category: it's only funny if you already think that equal rights for gay humans is a dangerous, left wing, anti-common sense notion.