ONE of the great things about Twitter is that you say things almost before you're quite sure what they mean. Last week, as Jeremy Corbyn was leaping on fire-engines to address streetfuls of supporters, I tweeted: "Only a gutless philistine would prefer one of Labour's cardboard leadership candidates over Corbyn. Politics is about morality".

It struck a chord. Hundreds retweeted and favourited this off-the-cuff remark. But there was a furious response from a raft of newspaper columnists who seemed to take it personally.

"Asinine" fulminated the Express columnist Stephen Pollard. Others including Philip Collins and David Aaronovitch of the Times and the Spectator's Alex Massie joined in the chorus of spluttering indignation.

Some clearly felt that I was passing moral judgement not just on the Labour establishment, but upon them. This wasn't my intention at all - journalists shouldn't adopt postures of moral superiority.

However, as readers of this column will know, I've often argued that politics is invariably about morality. Successful politicians of right and left articulate their policies in moral terms.

No Conservative goes about saying that greed is good and that the rich should be made richer; they argue that capitalism produces the greatest good for the greatest number and that private property bolsters individual freedom against the state.

Labour has always been a quintessentially moral movement based, as Tony Benn used to argue, on New Testament morality expressed in secular terms. Or as Harold Wilson put it: "Labour is a crusade or it is nothing".

Martin Luther King said he had a dream, not that he had a fully-costed plan to incrementally improve the democratic rights of minority groups in a way that would not antagonise the white anglo-saxon establishment.

Corbyn has a dream also, though being a streetwise Islington intellectual he would never express it that way (and, no, I'm not comparing him to King). It is the egalitarian vision, not his charismatic leadership, that's the root of Corbymania.

That's what has has attracted tens of thousands into the UK Labour Party. The response by the party establishment has been dismal. By launching an investigation into "left-wing entryism" Labour is inflicting a Spanish Inquisition on its own soul.

Corbyn's anti-austerity politics is not based on a narrow calculation of what policies might appeal to swing voters in the handful of marginal Middle England constituencies. He is saying that another politics is possible; another way of looking at the world; a New Jerusalem.

Which of course is why Labour's establishment believe he and his supporters are infected with "madness", as the former Labour health minister Alan Johnson put it last week. Echoes there of the attacks on SNP supporters before the Tsunami election.

They say: how could Labour possibly win with such an uncompromising idealist in charge? I mean look at him, in his Lenin cap and beard. Can you imaging Jeremy Corbyn attending a G8 meeting? Would Rupert Murdoch want to invite him to speak to News Corp on Hayman Island, as the media mogul did Tony Blair?

Can you imagine Jeremy Corbyn addressing the troops in Afghanistan or debating debt relief with Christine Lagarde of the IMF? Actually, stranger things have happened, as we saw during the Greek crisis. But that just makes the right-wing commentariat even more dismissive: we don't want Britain to end up like Greece.

The UK is, of course, a very different kettle of economic fish to the corrupt, de-industrialised oligarch-dominated Mediterranean state. Mind you, re-reading that sentence, perhaps the similarities are rather greater than we care to imagine.

Britain is, in many respects, a de-industrialised economy run by a corrupt financial establishment - one that was bailed out by £1.2 trillion of British taxpayers' money. It has continued to behave in exactly the same irresponsible and self-interested manner that caused the 2008 financial crash. The sell-off last week of RBS shares seems to have netted City speculators yet another windfall.

But does Jeremy Corbyn offer a realistic alternative? Does his brand of 80's neo-Marxism really stand up to scrutiny? Wouldn't Corbyn entering No 10 not lead to investors running in fright from the UK?

These are the cries of Labour "realists" like Alan Johnson, or Ed Balls who have been outspoken in their condemnation of Corbyn despite attacking him for disloyalty. Indeed, some Labour figures, like the ubiquitous spin doctor John McTernan, have been suggesting that Corbyn should be deposed by a coup should he actually win the leadership.

In reality though, Corbyn's policies are not really all that left wing. He is not advocating nationalisation of the "commanding heights" of the capitalist economy, nor is he seeking a dictatorship of the proletariat, a siege economy or even punitive taxation. You can tell this by the way other Labour leadership contenders are now adopting some of his themes.

Last week, Andy Burnham called for re-nationalisation of rail and the abolition of university tuition fees (though this was more apparent than real since he proposed replacing upfront fees with a graduate tax). This was an indirect tribute to the popularity of some of Corbyn's policies.

Of course, MPs like Jon Cruddas dispute this and say that anti-austerity policies are fatally unpopular with voters. 56 per cent of voters, he says, agree with the statement. "We must live within our means, so cutting the deficit is the top priority". That's hardly surprising though. It's all about the questions you ask. The same proportion, 56 per cent, agree with redistribution of wealth through higher taxation, according to YouGov.

In May, the SNP achieved the greatest General Election swing by any party in UK history on a policy agenda very similar to Corbyn's. Nicola Sturgeon's platform was infrastructure investment over deficit reduction; free higher education; unilateral nuclear disarmament; 50p tax band, a publicly provided NHS; gender equality, free child care etc.

We're always being told that Scottish voters aren't that different from English voters, so is there any reason why these policies couldn't be winners were Labour to have a leader of the same calibre as Sturgeon? (Jeremy Corbyn never really regarded himself as leadership material, though he's making a decent fist of it now.)

As I've argued before, when Labour under Tony Blair won its landslide in 1997 people weren't voting for the privatisation of the NHS, the restoration of tuition fees, illegal wars, renewal of Trident, or the celebration of gross inequalities of wealth. They voted for Blair because he articulated a vision of a more equal society. Blair stood for radical constitutional reform, engagement with Europe, investment in public services, and an end to class privilege and sleaze. Not that different really from Corbyn. And it was hugely popular.

Compare and contrast with today's "realistic" Labour candidates. Cooper, Burnham, Kendal have said little that is memorable or inspiring. They say, in essence: England is Tory, we must be Tory too. They don't really believe in austerity, but they have to pretend to in order to get elected. They offer only compromise and calculation. Theirs is a disingenuous defeatist "realism" that stifles creative thinking about society, regards inspiration as irresponsible and reduces moral vision to the tunnel vision of an accountant.

So, yes, I was right the first time. Corbyn may not win, but only a gutless philistine could favour that lot.