And yet, at just the same time, all around Mr Portillo, we have the opening of Schengenland, the borderless, shutterless continental space which symbolises free movement. And Schengenland, of course, excludes Britain. How could it be otherwise for a country ruled by a party which is emotionally addicted to shutters and congenitally suspicious of foreigners?
This implies a contradictory attitude to foreigners and an ambiguous attitude to our own country. Britain is rightly against the Brussels directive, not just because it is bureaucratic but because, as a low-wage and relatively poor European country, we need to let our people go abroad to earn money. (Mr Portillo's allies in Brussels were the Irish, the Portuguese and the Spanish, which tells us a bit.)
But we are against Schengen, because we don't want other people flooding in. We are, it seems, a curious country, which is economically poor enough to need to export workers to richer neighbours; yet so attractive that we are frightened of being "swamped" by abandoning our border-controls with the rest of the EU.
Now, it is perfectly true that our borders are not like other people's borders. Indeed, they aren't borders at all (with the exception of the Irish one) but a coastline. This, by definition, cannot be "internal" to the EU: beyond it lies the whole world.
So the argument goes that if we are to keep a check on terrorists, drug- smugglers and would-be illegal immigrants from beyond Schengenland, then we have to maintain coastal defences.
This has some merit, though it is hardly leakproof in logic. France has rather a lot of coastline too, yet this has not stopped it opening its road and rail borders with other countries.
There is another strong reason to be against the extension of Schengenland to Britain, which is that it would be used to force British citizens to carry identity papers. I loathe the idea, which smacks of leather-raincoated men moving through trains in war films, and which I think would lead to harassment and little-Hitlerism here. (Why don't Tory patriots make more of the unBritishness of this? Because, oops, most of these guys are passionately in favour of identity cards.)
So let us now admit the patently obvious. The Government is against Schengen not because it has weighed the pros and cons but because it could not possibly be in favour. Not in this mood of political xenophobia, which it has partly caused and which it hopes to use in an election. You can't go around implying that Abroad is a horrid place you get rabies and Brussels directives from, and then say oh, and by the way, we're dropping most of our passport checks.
The truth, though, is that the British have less of a foreigner problem than their politicians pretend. As in every other country, people here are susceptible to the argument that incomers might take away their jobs - that is a near-universal human instinct. But, with the huge exception of America, Britain has been one of the most open countries in the world.
Everything here is imported; and everything has been changed by being imported. This has always been a European country, heavily influenced by immigrants. Had Britain been left to the early immigrants, the Angles, Saxons and such, it would been a dreary dump today. It has needed regular "floodings" of outsiders to keep it fertile. Had there not been a heavy wave of Jewish immigration in the Thirties, what an intolerable city London would be now! (And by contrast, imagine how glittering and unlumpish Germany would be today had it kept, not killed, its Jews.)
Despite the political cant Britain remains unusually open, and because it affects our culture so strongly, the debate should be less about whether we want immigrants, than about which immigrants we most want.
We may, for instance, have rather overdone the white Commonwealth lot, who represent one of the most significant and least-discussed waves of modern immigration. Think of a City reception, where Sir Kit MacMahon, ex of the Bank of England, discusses the fall of Rupert Pennant-Rea with Win Bischoff, who runs the most-admired merchant bank Schroders, and Sir Alistair Morton of Eurotunnel. A typically blue-chip little British group - consisting of an Australian and two South Africans discussing a Zimbabwean.
Similar patterns can be found in business. The classically British Burton Group is chaired by John Hoerner, an American; British Aerospace is chaired by Robert Bauman, formerly head of SmithKline Beecham, from Ohio; there is another American, Richard Giordano, at British Gas; the quintessentially Home Counties Daily Telegraph is under Canadian ownership, and so on.
Culture is almost as outsider-tinged: imagine an Islington party with Clive James, John Pilger, Salman Rushdie and Bill Buford ... except these people aren't outsiders at all but, like the others mentioned, utter insiders. Why, they are almost as British as Sir Ralf Dahrendorf, Lord Weidenfeld or Edward de Bono.
At a more general level, Asian and Caribbean immigration has transformed urban Britain. As on the continent, there is a menacing degree of race hatred; the difference here is that the tension is not between pure native British and immigrants but between different waves of immigrants. Is there a single person alive today who can claim to be a "pure" native Briton?
Looked at this way, the problem of European immigration into Britain can be seen the right way round. The problem is not how to stop them coming here - it's how to get more of them.
As an immigrants' country, we are failing to get sufficient supplies of new blood. We failed very badly with the Hong Kong Chinese, whose energy and expertise we desperately needed - they have gone to Canada and the US instead. How are we going to get more Germans, more French, more Swedes and Spanish, to keep us pepped up, to keep the mix salty and strong?
The answer is we must do our best to keep politics out of this. European mixing is going ahead very well at the level of business, leisure, education and so on. London has strong and growing communities from most other EU nations; more and more middle-class Britons know that if their children are not fluent in French or German they will be handicapped in later life. Something bigger and better is happening than little Westminster understands.
Perhaps that is because, like the political classes of other countries, ours is still too doughily homogenous to comprehend the variety of the nation itself. For a country of immigrants, very few MPs carry immigrant names. Giles Radice is one and, of course, Michael Portillo is another; and in that, the man is a better herald of tomorrow's Britain than the words he sometimes utters.