Principled and brave, yes. But Davis still looks an oddball

Some sort of extraordinary brainstorm must have overtaken David Davis on Thursday night, an eruption of emotion that has persuaded him he can become the John Wilkes of the ID card age. His decision to quit the shadow cabinet and parliament - until he is re-elected, as he will be - can be explained by no ordinary political logic. It is as bewildering as a grown man collapsing into tears for what seems no reason; an expression of anguish and a search for attention from inside his soul.

The act is both very brave and very foolish, but either way it is confusing and will have consequences that Davis cannot predict. What it will do for the slow strangulation of British liberties, as he put it in a windblown statement on the steps of the Palace of Westminster after the Speaker meanly refused to allow him to make it in the Commons chamber, is uncertain - perhaps nothing. What it will do for his party is no easier to guess, except to say that it will be taken by Labour as Gordon Brown's best piece of luck in 12 months.

In a culture as monitored as British politics, there is something disturbing about anything done wilfully. Davis's decision has a reckless insanity that carries no sense of strategy - and which might come alive or crash and burn; as yet no one can know. It left his Tory colleagues by turns speechless and furious, an intentional jibe against their authority. It was a break from the collective, a bucking of the herd, an expression of individual freedom made in the cause of defending it.

His struggle will be to explain what he is standing for, and what it is he is against. His complaint is rooted in the government's policy on 42-day detention, but it sprawls much more widely, and risks turning into an individual manifesto rather than a single for-or-against question on an issue of controversial debate. There is a touch of the 18th-century Tory to his talk of lost liberties and Magna Carta, a backwoods defiance of Whiggish modernity in the name of protecting the roast beef and strong ale of old England. Hogarth would have been by his side, William Cobbett too, as well as today's rural protesters crying out about liberty and livelihood - but how is all this to be condensed into a case put to the voters of Haltemprice and Howden in a snap summer poll?

When Enoch Powell and his fellow unionists called byelections against the Anglo-Irish agreement in 1986, they could claim to be asking voters a question on something specific.

The problem is that for all the drama of his campaign, Davis only represents one form of liberty. He does not like the state very much, which other liberals rightly see as a necessary protection against social injustice. He has called for the return of the death penalty, backed section 28, and wants to scrap the Human Rights Act. What exactly is liberal about that? Magna Carta is all very well, but justice in this country depends on more modern protections, which do not all have his support.

How, too, can he expect to commit such an individual act without fracturing the Tory consensus, the preservation of which may prove vital to the 42-day cause he claims to represent? He has no public complaint to make about David Cameron or George Osborne; they voted by his side against 42 days and they have moved their party back into opposition to identity cards, though on the former issue both might have been open to persuasion if the government had attempted to talk them round.

They have been forced to offer tepid support for his move, while describing it as personal, which is the same as saying they would not have done it themselves. They will stick with the policy on 42 days and the new shadow home secretary, Dominic Grieve, will continue the fight as it heads into the House of Lords. But Davis's desertion halfway through makes little sense, unless it has been fuelled by other resentments.

He has behaved well since losing the leadership to Cameron when it looked as though he was certain to get it. There has been no sniff of disloyalty. But he must have been jealous of the younger Etonians who now run the Tories. He may have feared, too, for the party's future intentions on 42 days - although Grieve has confirmed a promise to repeal the law, if passed. There seems to have been no single row; rather yesterday's move was a show of defiance against establishments of all kinds, including the Tory one. The suspicion is that East Yorkshire's voters are being asked to back Davis's re-election without being given a full explanation.

Cameron himself sounded fraught in his statement yesterday. His fury at the way Davis has trampled all over the news is understandable. Cameron's anger may be tempered, though, by the thought that he will no longer need to defer to a leadership rival on home affairs, as Blair once had to leave the economy to Gordon Brown. But the impression of disunity will do damage.

As for other parties, Labour is trying to spoil Davis's day by not standing (hardly brave), while Nick Clegg's decision to do likewise was unavoidable, given he believes Davis's promise to confine his campaign to specifics. But some Lib Dems will hate it. Labour, too, will take note of Clegg's decision to back a Tory against the government, however unusual the circumstances and worthy the cause.

At a time when the political system is distrusted by the public it is supposed to serve more than ever, it may be churlish to pick on one man's desire to be different. Beyond Westminster Davis might become a hero for standing up to the system. He has at least created real drama about real concerns. All the wise heads who yesterday could see the illogicality may be missing the point: illogicality could prove to be the principle glory. And if there is to be a single-issue byelection, how much better it is, too, for it to be fought in defence of justice and individual freedom and not - as some other Tories might - on issues of migration or race.

For that, three cheers. Davis is right about 42 days, right about ID cards, right about the implications of a database-driven surveillance society. If he can explain in specific terms why he is staging this contest, and without lapsing into a little England grumble about all that is wrong with the state, he could yet achieve something magnificent. But the danger is that he will end up looking no more credible than a Fathers for Justice protester dressed in a Superman suit, jumping up and down angrily on Gordon Brown's roof.

Julian Glover