Miranda Green considers what the Lib Dems' strategy should be for the next election. Should they seek to share power for another term, or recapture their mantle as a radical insurgent? Can they combine both ambitions into a single platform?

Never go back, or so they say. As the Lib Dems prepare to gather in Glasgow for the second year in a row this October, the main topic of conversation has changed. Last year, the bars and fringe events hummed with discussions about whether the party had a good chance of getting into government again after the 2015 general election. This time, many voices will be questioning if such an outcome is even desirable.

Changes in voting patterns could make the 2015 election a second historic opportunity for the Lib Dems to share power. Neither the Conservatives nor Labour expect a thumping endorsement, and another coalition is still possible – one eminent pollster told me he would be 'astonished' if there are no Lib Dem ministers after next May.

But each week now seems to throw up another obstacle to those Lib Dems who hope that 2010's rose garden deal proves to be the beginning of a new era rather than a mere political curiosity.

The sharp pain of their dismal showing in the European election in May has faded to a dull ache of anxiety for a party that apparently faces another drubbing at the hands of voters, if not the wipeout that some of its enemies crave. (The party's ability to endure hostile conditions – its cockroach quality – is justly famous, and the Lib Dem vote-share remains healthy in its strongholds even as the national poll ratings look chronically sickly.)

Worse, the original Cleggite dream of selling the public a 'new politics', in which parties cooperate while remaining distinct at election time, has evaporated. Pressure on both the Lib Dem and Tory leaders to differentiate themselves has led to near-constant ministerial bickering. These displays have, in my view, been both tiresome to the public and self-defeating for a party that stands for pluralist politics. Yet activists and parliamentarians seem to want even more of them.

Some MPs, their minds on survival, are actively pushing the idea that staying well away from the booby-traps of office would give the Lib Dems a chance to recover and rebuild after the bruising effects of coalition on the brand and morale of the party. Another link-up with the Tories would put paid to more progressive alliances, they argue, while agreeing to work with Miliband after five experimental years with Cameron could look flighty.

Given these wobbles, waging a series of local battles to retain as many seats as possible has become the party's fallback strategy – the coming Lib Dem campaign will effectively be a ground war for over 50 simultaneous by-elections.

National messages, meanwhile, have become painfully difficult to fashion – not least because attempts to try out fresh lines have been hampered by the peculiarly accident-prone phase the party is going through. Lib Dem strategists released nuggets of new policy in a steady drip-feed over summer 2014, but these promises struggled to capture attention when pitted against background noise, particularly the ongoing Lord Rennard saga.

The affair made the party appear myopically addicted to its own complex internal democracy and processes. Has it even noticed the wider world turning against institutions with cultures and rules that fail the underdog?

Liberal Democrats should never be defenders of the powerful, of privilege or of the status quo. In the last three months, an appetite for the old anti-establishment provocations of the third party has grown – hence calls for more liberal drug policies, universal sex education in schools and similarly tabloid-baiting ideas. There has been a strong internal push to put out a bold manifesto rather than a checklist of policies that builds cautiously on coalition policy 'wins'.

But does the electorate want to be challenged, or would it prefer, in its current surly mood, to hear more reassuring noises? Some warn that hankering after the old insurgent energy of Paddy Ashdown's electoral guerrillas runs the risk of ignoring a newly-acquired asset: the chance to argue that Lib Dems, now tested in government, have proved their ability to handle power and make responsible compromises even when they are unpopular.

A 'core vote strategy' based on traditional Lib Dem ideas could be dangerous: just how small could the vote-share get if the campaign messages say nothing to voters who do not feel a burning love for the EU, nor wake daily from dreams of tearing down the House of Lords?

However, activists – who make or break election campaigns – need an injection of something to enthuse and motivate them. According to Ipsos MORI, Lib Dem supporters are the least likely to say that it matters to them who wins the next election.

Debates in Glasgow may become fiery if delegates perceive themselves as having to tussle with the leadership over whether the manifesto expresses the party's values, or becomes so diluted by the need to construct a basis for future coalition negotiations that it lacks any liberal flavour.

All this makes David Laws, education minister and longtime policy brains of the party, the most important individual at this year's conference. He is now called upon to perform a near-impossible trick. As the man in charge of producing the manifesto he must project new ideas that make voting Lib Dem a positive choice rather than simply a way to temper the excesses of a future administration that may lean too far to the left or right – and all the while ensuring that there is a credible core of policy demands that could be put to either a Conservative or Labour team in the event of another hung parliament.

Good luck, David.

Miranda Green is a journalist and former Liberal Democrat advisor.

This article appears in edition 21.2 of Juncture, IPPR's quarterly journal of politics and ideas.