In general, of course, it's unfair to reflect on a politician's partner, but in the case of the first husband and wife team to serve in a British cabinet, it's kind of inevitable. For nearly two decades, they've been seen as a single force. As a magazine pointed out in 1998, Cooper and Balls were 'New Labour's It Couple, the zenith of everything it stands for.' A Daily Telegraph profile of the pair the same year was headlined: 'Will this couple make it to Number 10?' Or, as the Guardian put it, they were 'the Posh and Becks of the Labour Party'.
Born in 1969, Yvette Cooper studied PPE at Oxford and went on to become an adviser to John Smith and to Harriet Harman. (My apologies for the repetitions in this series of portraits, but there really is a shocking lack of variation in the backgrounds of the candidates.)
She also worked for a while in journalism, as a leader writer and as the economics correspondent for the Independent. She was perfectly okay, and occasionally wandered out of her field. This is her on the supposed crisis in masculinity that was such a big media deal in the 1990s:
The only thing these men really have to adjust to is change itself. No, they can't have a job for life anymore. But so what? Few women ever had one. And no, they can't invest their entire identity in the firm they work for: the company might not be there in two years. And if they are too frit to visit their GPs they had better reconcile themselves to early avoidable death.No tolerance for the nanny state here, then; you sink or swim according to your own efforts.
Her articles tended to be broadly supportive of the Labour Party in opposition, but even she struggled to put a positive gloss on Tony Blair at times, and had to concede that his borrowing of Will Hutton's 'stakeholding' concept was little more than, in her word, 'waffly'.
Her ambitions, however, lay in Parliament not Fleet Street. Under the patronage of Gordon Brown, she attempted to become the candidate for the safe seat of Don Valley, where she lost out to Caroline Flint, before securing the nomination for the even safer Pontefract & Castleford, where she beat both Hilary Benn and Derek Scott (Tony Blair's economic adviser, who later wrote Off Whitehall).
She was one of ten Labour MPs elected in the 1997 landslide who were still in their twenties, and was clearly marked out for early advancement.
When Brown announced that he was handing over control of interest rates to the Bank of England, it was Cooper - just four days into her parliamentary career - who was sent onto Newsnight to defend the move to Jeremy Paxman. 'With that one step,' she wrote, 'the government has done more to achieve economic stability than anything any British government has done for years.' She brushed aside suggestions that the move was an affront to democracy: in characteristic New Labour style, managerialism was more important than politics.
Shortly after the election, Cooper and Balls - the archetypal North London couple - moved from Hackney to the New Labour heartland of Islington, though they later moved again, this time to upwardly mobile Stoke Newington. For expenses purposes, this was, of course, their second home, entitling them to a subsidised mortgage. When such things began to provoke outrage, it was reported that between them they had 'racked up more than £300,000 in expenses' in 2006-07, considerably above the national average for MPs.
From a whip's perspective, her behaviour in Parliament was exemplary, largely - one suspects - because she was a genuine believer in the Blair-Brown 'project'. The Demon Ears column in the Observer concluded that she 'isn't that bad for a New Labour MP, even though she does dream on message'.
By October 1998 she was being offered a minor government post, though she turned it down in favour of remaining a member of the intelligence and security committee. It proved to be only a short delay: the following year she took on the public health portfolio, becoming the youngest minister in Blair's administration. She then went on to become the first minister to say she'd once smoked pot and, admirably, didn't claim not to have liked it: 'I did try cannabis while at university, like a lot of students at that time, and it is something that I have left behind.'
In her new role she was partly responsible for the cross-departmental project Sure Start, widely seen as one of the better initiatives of New Labour. Its fanbase was wide enough to include, slightly oddly, a children's TV favourite: 'Peppa Pig is a well-known fan of Sure Start children's centres,' it was revealed in 2010.
Less successful was the idea of a crusade against teenage pregnancies under the slogan 'It's OK to be a virgin'. Cooper had sufficient political nous to reject that in favour of 'a straightforward campaign which gives teenagers the facts and is aimed as much at boys as at girls'.
She moved to the Lord Chancellor's department in 2002, then to environment, transport and the regions, where she became minister of state for housing and planning.
The latter portfolio did not count among New Labour's great achievements: during Blair and Brown's period in office, an average of 562 council homes were built each year, compared to the annual average of 41,343 during Margaret Thatcher's premiership.
Cooper did little to improve this woeful record, but she did do some things. She relaxed the regulations on householders installing small windmills and solar panels, and she piloted the chaotic introduction of Home Information Packs. She also faced criticism for allowing more house-building on flood plains. And she suggested that middle-aged couples in social housing should be encouraged to move out of cities when their children left home, to free up housing stock. Her concern here was over 'underoccupied' social housing, an issue later addressed - in somewhat more heavy-handed manner - by the Coalition government's bedroom tax.
When Gordon Brown became prime minister, she remained as housing minister but was given a new right to attend cabinet meetings, and then, in 2008, she made the cabinet proper as chief secretary to the Treasury. Just in time for the credit crunch, though happily she didn't stay very long. As Brown's government descended into a farce of resignations, her loyalty was rewarded with a further promotion, and she served out the rest of the New Labour years as work and pensions secretary, inheriting the agenda set by her predecessor James Purnell.
She spent most of the Ed Miliband era as shadow home secretary, one of the easiest jobs in politics, since there's always something going wrong in the Home Office to provide you with ammunition. This was, famously, where Tony Blair had made his name in 1992-94 in his 'tough on crime' days. But Cooper failed completely to make the same kind of impact and was largely invisible. 'Home secretary Theresa May was fighting for her political life last night as she was engulfed by the border checks scandal,' read the papers in 2011, but Cooper failed to exploit the situation, and of the two you'd probably bet on May being the one to make it to prime minister.
Perhaps, though, that job was a waste of her talent, which is much more obviously focussed on the economy. As shadow chancellor, she would have made a trickier opponent for George Osborne than did her husband.
Beyond economic matters, there has been much talk of women's issues, though sometimes this has been seen as being somewhat narrow in scope. Arguing, for example, in support of cuts to single-parent benefits in 1997, she displayed little interest in those who wished to concentrate on parenthood: 'It's a question of priorities. If we put resources into childcare and helping people back to work, we will raise the standard of living for the poorest.'
Similarly, she has repeatedly claimed over the last few years that 'David Cameron has a real problem with women'. This is an over-simplification, seeming to imply that women can be seen as a homogenous, metropolitan, professional block, somewhat in the image of Cooper herself.
The reality is that age is as big a factor as gender. At the election this year, according to Ipsos-Mori, Labour had a 20-percentage-point lead over the Conservatives among women aged 18-24, but trailed by 18 points among women over the age of 55. Unfortunately for Labour, which clearly has a real problem with older women, there are considerably more of them, and they're more likely to vote.
Cooper considered standing for the leadership in 2010, and Balls said that if she did so, he wouldn't stand himself. She decided against it, however, because she wanted to spend more time with her children. Five years on, and it was inevitable that she would be a candidate. By any normal standards, she really ought to be the front-runner, the one that the others have to beat. But that's not how it's worked out.
In 1997 she condemned - with complete justification - the Conservatives for their remoteness: 'They took politics far away from normal people's lives.' She points, with some justification, to Sure Start as her contribution to changing that, but as a politician, she herself doesn't seem to connect. There's something that isn't quite right. Perhaps Simon Hattenstone put his finger on it in the Guardian in 2010. 'It's funny that Cooper seems so human till she starts to talk,' he wrote, 'while Balls seems so monstrous till he starts.'
This is the third in a series of profiles of the four candidates in the Labour Party leadership election. Yesterday: Liz Kendall. Tomorrow: Jeremy Corbyn.