Every electoral defeat also produces a winner, and seldom has this old political rule been truer than in the case of Britain.
Prime Minister Theresa May has spectacularly failed to win an overall majority in the recent general election despite starting the campaign with her Conservative Party running 20 points ahead of her opponents, yet still gets to stay in power largely because of the startling success of another woman in her party: Ms Ruth Davidson, the Tory leader in Scotland.
Like Mrs May, Ms Davidson passionately believes that the Conservatives remain the only political force able to run a Britain which faces both the huge challenges of leaving the European Union, and of keeping the country united in the face of Scottish separatism and potential economic decline.
Unlike the Prime Minister, however, Ms Davidson is seen as being able to deliver on both promises; even her sworn opponents accept that the 38-year-old Scot is Britain's fastest-rising political star.
Ms Davidson's chief weapon is her ability to defy all social stereotypes. She comes from a working-class family, yet leads the Conservatives, associated in the Scottish public's mind with county squires, wealthy landowners and women dressed in twin-sets and pearls. With a degree in English literature, she worked as a journalist before volunteering for military service as a signaller, hardly a traditional career path. And, in a party which values social conservatism and family values, she is not only openly gay but also a vigorous campaigner for gay equality rights.
Unsurprisingly, her way to the top of her party was not easy. She narrowly secured the leadership of Scotland's Conservatives in 2011 after some stinging electoral defeats, and she was often on the receiving end of attacks in the media for her sexuality, with the Daily Mail, which claims to stand for core middle-class Conservative voters, once dismissing her as a "lesbian kickboxer".
But she confounded all her enemies by turning what were initially perceived to be political handicaps into assets. "This idea that we've all had a gilded youth just isn't borne out by the facts," she once said in response to accusations that she represents the party of social privilege.
Ms Davidson's chief weapon is her ability to defy all social stereotypes. She comes from a working-class family, yet leads the Conservatives, associated in the Scottish public's mind with county squires, wealthy landowners, and women dressed in twin-sets and pearls... And, in a party which values social conservatism and family values, she is not only openly gay, but also a vigorous campaigner for gay equality rights.
And, in 2015, she became the first British politician to appear in an official electoral campaign broadcast with her same-gender partner. The two got engaged last year, but postponed their planned wedding in order to pay the vet's medical bills after their dog was hit by a car. Such gestures would have come across as artificial from any other politician. But not from Ms Davidson.
She is a politician with a shrewd sense of timing. Although Scotland voted to remain in the EU but was overruled by the rest of Britain which voted to leave, she refused to accept that this justifies holding another vote on independence.
So, when Ms Nicola Sturgeon, Scotland's First Minister and head of the Scottish National Party (SNP), decided to make the demand for another independence referendum a key plank of her campaign, Ms Davidson turned the tables by making education and good governance the key issues of the election.
She also publicly took on Scotland's separatist leader, who hates to be contradicted. "Argh... shut up," she recently told Ms Sturgeon during a parliamentary debate, to the wry smiles of everyone who knew how difficult such a request was.
Ms Davidson's electoral tactic worked brilliantly. The number of Conservative MPs in Scotland jumped from one to 13 at the recent election - a shift which not only humiliated the SNP, but also ensured that Mrs May remained in office in London. Ms Davidson is the United Kingdom's real kingmaker.
Many see her as a future British prime minister. But her biggest contribution may be to keep the UK united by remaining in Scotland, where she is the only person able to deflate the SNP and its separatism.
That may also mean periodically disagreeing with the government in London, as she has done when she publicly called on Mrs May to tone down her "hard Brexit" plans to sever all links with the EU and go instead for what Ms Davidson cleverly termed an "open Brexit", which prioritises the preservation of British business interests instead.
Being a thorn in the flesh of separatists in Scotland and also the central government in London will not be easy. But it does not daunt Ms Davidson, who has now set her eyes on becoming Scotland's First Minister in elections scheduled for 2021.
And she can rally all of Britain while maintaining her distance from London. While a dejected, grimacing Mrs May was addressing her party faithful last week in the wake of her election setback, Ms Davidson was delivering a rousing speech to the Tories in Scotland.
Nobody doubted who among these two British politicians stood for the country's future.