A hysteria grips this fair country of ours.
It is not a feverish fandom for a footballer or a pop group or a shiny new gadget.
It is not the 950,000 signatories to the petition to reinstate Jeremy Clarkson to a job from which he has not been fired. (Though these are profoundly odd people and you probably shouldn't allow them to look after your pets, plants or children.)
Nor is it the exuberance of Scottish Nationalists, their various shades of Yes badge distributed 15 per lapel, who refuse to lose the independence referendum.
No, the mania stalking Britain is quite mundane as manias go, and is more likely to affect the mature, the reserved, and the customarily polite.
Quite simply, Britain has lost the plot when it comes to immigration.
A case in point is the Home Office minister, Lord Bates. In the course of answering a question on immigration in the House of Lords on Monday, the Conservative politician told their noble lordships:
"In the year ending December 2013, an estimated 7.8 million people were born outside the UK, while 4.9 million were non-UK citizens. For the calendar year of 2013, births in the UK to non-UK born mothers accounted for 25% of all live births. That is why we need to reduce immigration."
If you're wondering what the big deal is, you too are probably fixed by the hysteria or could be showing early symptoms. Stay with me for a few minutes and I promise to help you.
The contentious part is those eight words tacked on at the end of his statement.
"That is why we need to reduce immigration."
Immigrants are coming here and having too many children. We must stop this social ill by cutting immigration. It is an extraordinary thing for a politician to say.
In 1974, the Conservative MP Keith Joseph gave a speech on social policy. Reading it again today, it sounds a tad curmudgeonly in its youth-gone-wild moralism but it is undoubtedly the composition of an intellectual. Joseph drew on the work of Orwell, Freud, Rousseau and, somewhat less illustriously, Mary Whitehouse.
But near the end of his remarks, Joseph inveighed against the late unlamented bogeyman of the Tory Right: Unmarried mothers and the "problem children" they bring into the world. "The balance of our population," he ventured, "our human stock is threatened." Allowing these young women easier access to birth control was far from ideal but perhaps expedient, he implied.
Joseph's critics accused him of promoting eugenics (which he really wasn't doing) and he lost his opportunity to become leader of the Conservative Party, clearing the way for Margaret Thatcher.
We should be careful not to overreact to Lord Bates' comments and they certainly contain no hint of the repugnant pseudo-science of eugenics. But having read and re-read his remarks, I cannot reconcile the horror most Conservatives would express were Joseph's words to be spoken today with the middling response to the minister's statement.
The impeccably right-wing Spectator editor Fraser Nelson tweeted:
I've no doubt many sensible right-of-centre people agree with him but the failure of the Prime Minister to rebuke his minister swiftly and firmly is dismaying. This omission, whatever the behind-the-scenes machinations, unhelpfully juxtaposes itself with the frenzy of anti-immigration rhetoric issuing forth from the Conservative re-election campaign.
It is worth noting that Lord Bates was answering a question from Lord Green of Deddington, formerly plain old Andrew Green, the chair of MigrationWatch. MigrationWatch describes itself as a "think tank" and advocates "sustainable levels of properly managed immigration", which is to say dramatic reductions in the annual number of people coming to live here "to the low tens of thousands".
As a frequently aired voice on the BBC and in the tabloid press, MigrationWatch has perfected the art of assuring us it thinks some immigration is valuable before going on to warn that unless we cut the numbers soon, we'll have to build "the equivalent of the city of Birmingham" every other year to cope.
MigrationWatch is beloved of the right-wing of the Conservative Party, which is perhaps why Lord Bates followed up his call for cutting back on these overly fertile immigrants by "pay[ing] tribute" to Lord Green and lauding MigrationWatch as "a balanced think tank that makes a positive contribution to the debate on immigration in this country".
Time for some perspective. According to research by the Centre for Research and Analysis of Migration at University College London, European immigrants put more than £20bn into the British economy between 2001 and 2011, £5bn from eastern Europe and £15bn from the rest of the EU. Non-European immigrants chipped in £5bn during the same time period. These immigrants were 43% less likely than people born in Britain to claim welfare benefits. European immigrants are more likely than Britons to be degree educated and the skills they brought the labour market during the Noughties would have set the UK taxpayer back £49bn to impart through our own schools and universities. Overall, immigrants were estimated to have contributed around £82bn to public goods between 1995 and 2011.
You're a pretty well-educated crowd. Hands up if you didn't know any of that?
This is the problem. Our national discourse on immigration is governed by ignorance rather than evidence. True, politicians are following the public mood which is hostile but it is the job of leaders to lead on matters like this. (Oh and before any fellow Scots try to pull the 'anti-immigrationism is an English phenomenon; Scotland warmly welcomes newcomers' line, I'd suggest venturing beyond the salons of Byres Road once in a while. A January poll carried out by Panelbase for Wings over Scotland found 69% of Scots thought there was "a problem with too much immigration in this country", just two percent lower than voters in the rest of the UK.)
For their part, the Conservatives have pursued a relentlessly negative agenda on immigration. The liberal-Left denounces ministers for pandering to base impulses towards foreigners. Their real sin as Tories is acquiescing in the economic and demographic illiteracy that distorts the debate on immigration.
If you believe the state should limit the free movement of labour and block the inward-investment-on-two-legs that every immigrant represents, you're probably not an economic liberal. If you would prefer to spend vast sums of taxpayers' money subsidising native-born Britons - and only native-born Britons - in careers as doctors, teachers, and firefighters, I hate to break it to you but you're most likely not a Thatcherite. A protectionist, yes. A corporatist, perhaps. A believer in free markets and individual liberty? Not so much.
There is a debate to be had. Immigration is not an unalloyed good and plenty of legitimate questions hang in the air. How do we address the housing strain already with us and which can only increase with a growing population? How do we ensure immigrants integrate, accept basic liberal and democratic precepts, and what do we do about those who won't? Do we want to be a "multicultural" society, where distinctive (some might say insular) groups bump up against each other, or a "melting pot" into which people from all backgrounds and parts of the world chip in their values and experiences to forge a cogent British identity?
None of these should be no-go areas for reasoned discussion. Those who seek to cordon them off are demagogues no less than the xenophobes. But reasoned is exactly what the current debate is not. Deranged might be a more appropriate description.
Tim Montgomerie laments the "Crosbyisation of the Conservative Party", a reference to David Cameron's Australian campaign strategist Lynton Crosby. Mr Crosby is notorious for his bare-knuckle approach to political combat and his right-wing populist mindset. The decision to ditch the "compassionate conservatism" touted in opposition in favour of a run to the right and an avalanche of negativity about the Labour Party can be traced to Mr Crosby's influence.
And so we find ourselves in the situation where a growing constituency of ambitious and industrious new voters, driven here by aspiration and in pursuit of hard work and better lives for their families, are pushed away by the very party that is supposed to stand for all those things. And not just pushed away but traduced, abused, and demonised.
The Tories' strategy to win the 2015 General Election looks remarkably like a campaign to lose the Britain of the future.
No wonder John Stuart Mill called them the stupid party.
Stephen Daisley is STV's digital political correspondent. You can contact him at firstname.lastname@example.org.
Image of Lord Bates (c) Foreign and Commonwealth Office via Creative Commons 2.0. Cropped.