“Are you a liberal, or are you a feminist?” That’s the question that Jo Swinson was asked at a closed-door hustings for Liberal Democrat peers. Her answer was that you couldn’t be one without the other, which irritated some of the lords. Swinson enjoyed a better response in another closed-doors hustings, that of party workers. The questions there were light on ideology and heavy on organisational matters, and her answers revealed, as far as the assembled aides were concerned, a politician who had thought deeply and seriously about how to run the party.

In the end, Lib Dem members found they had more in common with staffers than with the party’s peers, and elected Swinson by a landslide margin on 22 July.

The reality, despite what some Liberal lords might have thought, is that there was no great ideological divide in this contest. Both Swinson and her defeated rival, Ed Davey, were inspired to join the Liberal Democrats by Paddy Ashdown, whom Davey worked for and at whose leaving party Swinson met her husband, Duncan Hames. For the first time in the party’s modern history, neither candidate had a particular fealty to either the pre-merger Liberals or to the Social Democratic Party, which broke away from Labour in 1981.

The contest between Boris Johnson and Jeremy Hunt ought to have presented the Conservative Party with two significantly more divergent futures. On the one hand, Johnson, who surprised nobody by following Swinson’s victory with a landslide of his own, had set out a series of red lines that can only end in a no-deal Brexit. But Hunt failed to keep up his end of the bargain. His Brexit position changed almost every week in what his allies described as an audacious attempt to steal Johnson’s clothes and win the leadership, and his growing band of detractors saw as a naked bid to extend his political shelf-life into the Johnson era.

Even a generous marker would have to describe Hunt’s leadership bid as an unremitting failure: not because he couldn’t stop Johnson, which was probably impossible, but because he proved incapable of articulating or holding an anti-Johnson position.

But what ultimately doomed Hunt was that Conservative MPs and party members had decided, well before the contest had truly begun, that the number one qualification for their next leader would be their suitability to take on Nigel Farage and the Brexit Party – a calculation that led, inexorably, to Johnson. Little, if any, attention was paid to the fact that while a Johnson premiership may send the Brexit Party to sleep, it does so at the cost of putting the Liberal Democrats and the SNP on steroids. It leaves all 13 Conservative MPs in Scotland – without which the party would not be in office – in varying degrees of jeopardy in the event of a general election, particularly if Brexit is unresolved. And despite Johnson’s repeated promises not to call an election until the UK has left the European Union, parliament’s resistance to a no-deal Brexit means that, if Johnson wants to keep his promises, he will have to go for an election sooner rather than later. It’s this certainty that makes the

Liberal Democrat leadership so important.

Something both parties privately acknowledge is that the Lib Dems will do better – at least as far as votes cast are concerned – at the next election than the last one. Although Tim Farron, who led the party into the 2017 contest, was instrumental in declaring the party opposed to Brexit in all forms, against serious internal resistance, his social conservatism made him an ill-fitting leader for a Remain revolt. And questions over his attitudes to homosexuality and abortion blighted his general election campaign. Swinson’s comfort in describing herself as both a Liberal Democrat and a feminist makes her well placed to appeal to the section of the public that believes Brexit should be resisted come what may.

Yet the big question is: where will those votes come from? The evidence from the polls and European and local elections is that they largely come from the Labour Party – analysis by Jeremy Corbyn’s strategists shows that for every four votes Labour has lost since 2017, two go to the Liberal Democrats, one to the Green Party and one to the Brexit Party. But the evidence also suggests – including the Liberal Democrats’ own advanced MRP YouGov modelling, using the same methodology which accurately predicted the outcome of the 2017 election – that while the Liberal Democrat revival is taking Labour’s votes, it is costing the Conservatives more seats. Of the 82 seats that the Lib Dems hope to make their major targets, just three – Sheffield Hallam, Leeds North West and Streatham – were won by Labour in 2017. Only one, Southport, is a seat where Labour is even in contention.

That calculation shapes every move that Swinson and her party will make. They have ruled out a coalition with a Corbyn-led government but kept the option of an alliance with another Labour politician open. The voters they need in order to gain seats are those with doubts about a Corbyn government in Conservative-held seats in the south of England and outer London, rather than Labour defectors trying to send a message to Labour in the country’s big cities.

The big Conservative hope is that while Swinson will cost them seats directly, she will indirectly tip Labour seats into their hands in Labour-Conservative battlegrounds – if the Liberal Democrat vote goes up at Labour’s expense and the Tory vote holds steady. Is the gamble right? Either way, that the Conservatives have picked Johnson, whom many liberal voters dislike, as their standard-bearer means that they have little chance of ending the Liberal revival – they can only hope that they lose less from it than Labour. Whether they realise it or not, the politician they are placing their hopes in isn’t Johnson but Swinson.