NORTHFIELD, a constituency on the southern tip of Birmingham, possesses all the features of post-industrial exurbia. Its biggest employer, the MG Rover car plant, closed down in 2005, throwing 6,000 people out of work. The most conspicuous buildings are supermarkets. The district shows some signs of life: the old Rover plant has sprouted an innovation centre and the Cadbury’s chocolate factory still operates, though under foreign ownership. But there is a sense that people are holding on by their fingertips. “This is where normal people live,” says Meg Powell-Chandler, the local Tory candidate.

Ms Powell-Chandler was dropped into this unpromising constituency at the last moment: she didn’t know the place well, having grown up as a country girl in neighbouring Worcestershire, and had to interrupt campaigning to get married (“Weddings are too big a sunk cost to cancel”). The sitting Labour MP, Richard Burden, has held the seat since 1992. Yet when she says that she has a good chance of winning, she is doing more than indulging in a candidate’s compulsory bravado. Mr Burden’s majority has fallen from 29 percentage points in 1997 to six points in 2015. The constituency voted for Brexit by 62%. The Conservatives’ successful campaign to make Andy Street mayor of the West Midlands has left them with infrastructure and momentum.

Ms Powell-Chandler is part of a concerted Conservative attempt to advance into Labour territory. The Tories launched their manifesto in Halifax, a Yorkshire town with a long history as a bastion of the Labour Party. Theresa May’s itinerary looks like a guided tour of post-industrial Britain. The central pitch of her manifesto is that the state has a duty to protect people against the vagaries (including immigration) that can make it impossible to cling onto respectability.

The Tories’ election campaign has lost its sense of inevitability to mixed polls and backbiting. But it is worth bearing two things in mind. The first is that the Conservatives have made most of the running: Labour has been fighting to defend its home turf by campaigning in Labour constituencies and promising to expand the welfare state and nationalise industries. The second is that the Tories’ strategy is a bold one. They believe that the inhabitants of post-industrial Britain have been ripe for the picking for years—these are the grandchildren of industrial workers, who belong to the world of Netflix and all-you-can-eat buffets rather than the mill and the chapel—and that the plucking has been made even easier by three recent events: the rise of Jeremy Corbyn, the selection of Mrs May and Brexit.

The blue-collar strategy was responsible for the biggest mess-up of the campaign. The decision to include a pledge in the manifesto to require old people who live in valuable houses to meet more of the costs of their in-home care was intended to demonstrate that the Conservatives are not just the party of elderly, rich southerners. It went down well with working-class voters, who didn’t see why they should pay for the care of people in million-pound houses. The problem was not just that the policy failed to put a cap on how much people might pay. It was that it revealed the clash of interests between the people the Tories already represent and those they want to convert.

It was also responsible for the biggest frustration of the campaign: Mr Corbyn’s failure to self-destruct. The Conservatives calculated that working-class voters would instinctively prefer Mrs May, a proud product of middle England, to Mr Corbyn, a hardline leftist who represents a trendy bit of London, Islington North. But the story has been more complicated. Mrs May’s refusal to turn up to a debate with the leaders of the main parties on May 31st made her look weak. And Mr Corbyn’s long record of backing hopeless causes has made him look strong and stable. Ed Miliband, his predecessor, irritated voters because he always seemed to be apologising for himself. Mr Corbyn doesn’t think he has anything to apologise for.

Yet even if the going is tougher than the Tories imagined, the strategy may still yield results. The clearest reason for this is Brexit. Post-industrial England and Wales voted overwhelmingly for it, and leavers seem to feel more strongly than remainers. Hampshire is not likely to go Labour but Northfield may well go Tory. The less obvious reason is people like Ms Powell-Chandler. David Cameron’s modernisation of the party has yielded a crop of sensible-looking and hard-working candidates who are now trying to sell the Conservative brand in unfamiliar territory.

Tricky to collar

Bagehot’s whirlwind tour of working-class constituencies in the West Midlands, Northumberland and Durham suggests that opinion is in flux. People are angry with the political establishment, annoyed about being asked to vote again and disappointed in the choice on offer. Labour voters are divided over their party, responding to Mr Corbyn’s call for a more just and generous society but worrying about some of his views—particularly his lack of patriotism—and his incompetence. And there are a growing number of outspoken Tory supporters deep behind Labour lines. Raymond, a tattooed Glaswegian who has lived in Bishop Auckland, a Durham constituency, since 1995, proclaims that he will be voting for Mrs May because “I’m a Brexit man. I want the politicians to be accountable to the people—I’m sick of them hiding behind Europe.” He adds that his wife loves Theresa.

The most interesting seats to watch will be traditional Labour ones like Northfield and Bishop Auckland. Failure there will mean that Mrs May’s strategy has flopped and that her future is in doubt. Success will not only indicate a big Tory majority. It will suggest that a significant political realignment may be in progress, with the Tories becoming a one-nation party again and Labour, cut off from its working-class roots, becoming the party of public-sector employees and professional protesters.

Economist.com/blogs/bagehot