The tribal politics that are saving Blair's skin

Some of these - the growth of state authoritarianism, our leaders' imperviousness to accountability or shame - are well understood.

But Blair signifies another issue of our time, too: the deep confusion about what it is to be progressive. It is simply fascinating that all Sir Ian's main defenders place themselves on the Left; and many, though crucially, not all, of his main critics are on the Right.

But what does progressiveness mean any more if Ian Blair can be defended as a progessive? His policy on detention, surveillance, free assembly and stop-and-search is the most illiberal of any serving Commissioner in history.

Nor is terrorism any excuse. Western liberalism is what the terrorists want to destroy. So this is precisely the time when progressive values most need to be defended.

For some of Sir Ian's allies, of course, it's simple, if stupid, tribal politics: the Tories are against him, so Labour must be for him. Sir Ian has supported Labour policy well beyond the call of duty. There's also the natural solidarity of the people-in-power club, and Labour happens to be in power.

And there has always been a strong streak of authoritarianism on the Left. Changing the world in a hurry has always involved elements of compulsion. But what's new is that, having surrendered to the free market, Labour's authoritarian idealism has moved from the economic into the personal sphere. They want to tell us what we can eat, where we can march, what papers we must carry.

Yesterday on the BBC, Ken Livingstone gave his usual backing for Sir Ian - but also, just as interestingly emerged as a strong supporter of ID cards. In a quieter way than, say, Tony Blair invading Iraq, Ken's political journey over the past few years charts Labour's decay as a progressive force.

There is another factor behind "progressive" support for Sir Ian. Clumsy as he is at the macro politics of his job, the Commissioner is quite good at the micro politics - the stroking of relevant politicians and self-appointed "community leaders".

On race, where Sir Ian is praised by "progressives", his record is actually very mixed. Talk to ordinary non-white Londoners and you will often find them furious about their disproportionate targeting for stop-and-search.

Sir Ian has been at loggerheads with his own senior black officers, who find it curiously hard to get promoted. Only last week, it emerged that a 52-year-old black engineer, the victim of a hijack, found himself detained for "stealing" his own car.

But away from that harsh real world, in the politicians' parallel universe of "consultative groups" and "community forums", Sir Ian shines. He goes to the meetings. He has mastered all the right phrases from the race-relations handbooks.

Sir Ian is backed because he has learned the real secret of being " progressive" in Brown's Britain. It's not what you do that matters. It's what you say.