Why Corbyn could prompt a Tory lurch to the Left
It's not often that the political earth moves, but we can expect some tremors at about noon today if - as almost every Labour MP expects - Jeremy Corbyn is elected leader. Ed Miliband lost the last election because he dragged his party too far to the Left. So rather than compromise with the voters, Labour has lurched even further to the Left. We're witnessing a suicidal charge of the red brigade: magnificent, perhaps, but it's not politics.
George Osborne is already circling like a vulture over this battlefield, appearing in the New Statesman and preening in front of its Left-leaning readers.
This may not be terribly effective; his attempts at self-deprecation are in their infancy and can sound as alarming as his boasts ("I realise, of course, that not everything in the country happens inside the Circle Line," he says at one point, "and that's been a very important development for me as an adult.").
But his overall strategy is, as so often, precisely right. Labour is not just running off to the Left, but running away from its core voters. The Tories must now run towards them.
About half of Labour's supporters may now be up for grabs, judging by surveys of their attitudes. About half have opinions that Corbyn abhors. These are the people who once voted for Thatcher and then turned to Blair, but never quite warmed to Cameron.
They're concerned about social justice, but are not starry-eyed, envious or vengeful. They like the benefit cap, and think those who turn down work should lose benefits. They think defence cuts have gone too far. They don't share his desire to whack the rich; indeed, they want to raise the threshold for the 40p rate of tax.
Corbyn is preparing to make some concessions; he says that he's prepared to wait for the abolition of the monarchy and has refrained from condemning the RAF's elimination of a jihadi in Syria (which Labour voters back by a margin of four-to-one).
His other batty ideas are still in place, from "people's quantitative easing", to his terrifying fondness of Sinn Féin and Hamas.
And throughout this seemingly interminable leadership campaign, he has had nothing sensible to say about the most important question: why did Labour fail to win?
Tories are much concerned about this. Lord Ashcroft has been busy asking ex-Labour supporters why they defected, and he published his research yesterday. The most frequent answer was that Miliband was not a credible prime minister and led a party that no longer seemed to represent them.
If Miliband was too ideological for such voters, then Corbyn may well prove to be the most effective recruiting sergeant in the Tory party's history.
But only if (and it's a big 'if') the Tories play it right.
British prime minister David Cameron does not need to adopt genuinely damaging Labour policies. He just needs to highlight how his own ones are working - conservative means, but progressive ends.
"Let the broadest shoulders bear the biggest burden," runs Corbyn's slogan. Under Osborne, the best-paid have been shouldering a greater share of the burden than at any time in history. Why?
Because he cut the top rate of tax. Lower tax rates led to higher tax revenues; this is what John F Kennedy referred to as the "paradoxical truth" of taxation. But it's one that Corbyn is ideologically unable to grasp.
Several of Corbyn's proposals have been tried over the decades and left a trail of political destruction.
Ask low-paid workers in Stockholm or Manhattan if his proposed rent controls are a good idea. Ask Zimbabweans how 'People's Quantitative Easing' worked out for them.
Corbyn is offering fantasy policies for a fantasy world - but it's not enough for Cameron to hold them up to ridicule. He needs to occupy the political space that is about to be vacated.
He must ask: what would a sensible, effective Labour Party leader be saying? And then say it himself.
In a way, he should become the opposition to his own government - which is less bizarre than it sounds.
Take Theresa May's brilliant work with modern slavery; she thrust the issue on the agenda and campaigned on it as home secretary.
She highlighted how people are being kept in servitude in today's Britain, with the police failing to recognise victims and lacking the powers or incentives to prosecute slave masters.
Her remedy was the Modern Slavery Act, a triumph of modern progressive conservatism.
In the last parliament it was a Conservative, Michael Gove, who campaigned about the need to close the disgraceful attainment gap between rich and poor in state schools.
His reforms were devoted to helping the less advantaged and the results have been extraordinary. No wonder the idea of teachers starting up their own schools is at its most popular in the poorest communities: they need the help most.
They can least afford to gamble with ideological flights of fancy. (© Daily Telegraph, London)