I spent a very long time yesterday at the wedding of a young Hindu woman and a young man who is a dyed-in-the-wool conservative who used to work for Birmingham City Council Leader, Mike Whitby. It was a really pleasant occasion to be able to watch the two extended families from different cultures mixing so freely and giving their blessings to the couple. It is rare I get the opportunity to talk to Conservative Party activists, we tend to move in different social circles. During one of the delays between the two cultural weddings I got to talking with a young ambitious Conservative woman. I promised not to blog about her indiscretions about various Tories, although she did reveal that quite a few Tories actually feed subversive information to Political Hack, but one of the things that struck me was how dismissive she was of the Tory 'Old Guard'. She backed Cameron and his 'social conservatism' with a passion and sneered at the right wing of her Party with a venom usually reserved for those of us on the left of the Labour Party by our so-called comrades from the right.

So, in the context of all that, I was interested to read Portillo in The Sunday Times today. Writing about Cameron's attempt to shore up the traditionalists, Portillo says:

Had Cameron, a few months back, when he was 10 points ahead in the polls, adopted the tough tone on immigration that he used last week, he might have looked more like a man playing an ace (although I doubt it). But raising it now that he, too, is trailing, just looks like Tory despair once more.

It seems, anyway, to hinge on a misreading of his problem. He is not behind in the polls because he has lost Tory support. He has lost Tory support because he is behind in the polls. He fell behind because he failed to hold on to the new supporters that, with his freshness and his shift to the centre, he had won over from the other parties.

Those are the voters who will be most put off by Cameron’s mentioning immigration. They think it grubby Tory politics. They may be middle-class and otherworldly types who can afford to be liberal because they never encounter an immigrant other than their cleaner or plumber, but they have the votes that Cameron needs. By raising immigration in an attempt to shore up his core support, he has put those new votes beyond reach.

In fact, the core vote will not be mollified either. Over many decades, it has repeatedly heard promises to tighten up on immigration. But new arrivals have gone on arriving. First came West Indians to meet the shortage of labour, then new Commonwealth immigrants, then Kenyan Asians, then the families of all the above, then asylum seekers and lately European Union migrants (again to top up the labour market). For all the Tory party’s Euroscepticism, it was at least as keen as Labour on enlarging the European Union and allowing the free movement of people, so there was no choice there either.

So when Cameron raised immigration last week it seems highly unlikely that anyone will have thought: “At last, a politician determined to make a difference.” They will probably have greeted his pronouncement as something wearisomely familiar, commonly associated with Tories around election time. It is hard to see what Cameron could have gained with it, but easy to see what he may have lost.