How miserable are you feeling as you contemplate 2020? Putting aside our individual circumstances, the answer is often closely linked with how we are minded politically. A series of body blows to centrist thinking since the honeymoon period after the cold war gave way to a financial crisis and bitter backwash, followed by the arrival of Donald Trump and a gaggle of nationalist-populists around the globe. Add a resounding Boris Johnson majority at home, midwifing a Brexit on untrammelled terms – and liberal grumpiness has its reasons.

But it feels like the right moment to ask whether the gloom-deploying strategy has been so smart. A far-left Labour party served up a recipe of predictions of disaster to dim the fairy lights of the holiday season – and suffered calamity at the polls. More broadly, liberals (and not just the Lib Dem kind) need to think about how unattractively miserable they have become and what they might do about it.

One key reason Johnson has prevailed is his ambition and direction. This is being linked with a less attractive character trait, namely recklessness. But here is a politician who has carefully exploited Barnumesque moments to emphasise that he is different from the dreary run of his peers. Some people deem that innately hilarious; others find the antics and confection of his speeches wearing – a man-child in leader’s clothing.

Still, it would require a political tin ear not to heed his appeal to parts of the country that rejected his party’s forebears with such gusto.

North-west Durham, where I grew up, and nearby Bishop Auckland (which has acquired Agincourt significance for victorious Conservatives) are two such fiefs. They switched political course in large part because they were fed up waiting for the Brexit moment to come and because of the not unreasonable view that if you feel left behind in an area where for decades the only language has been Labour, it makes sense to change the language.

A stalwart Labour-voting friend in a Durham constituency told me a couple of weeks before the election that he kept encountering people who were considering switching intentions because Johnson was “someone you could sit down for a beer and have a laugh with”.

Back in the enclosed political drawing room of Remainy central London, the denunciations of his moral turpitude were a repeated theme. “I wish he would just go away,” snapped one acquaintance (pointlessly, it turned out).

Reality check – it was Anna Soubry’s Independent Group for Change that shut up shop at the end of 2019. When I email a prominent Tory defector to the Lib Dems to ask what comes next, he replies simply: “Time to do something else.” Sands today shift extremely fast and perceptions can differ widely, even before we reach the extremes of politics. Where Johnson’s critics saw egregious moral weakness, an on-off relationship with the truth and a threadbare promise to deliver more spending while dealing with the economic and logistical challenges of leaving the EU, a lot of other people disagree. As one of his cabinet puts it: “Boris is a personal Rorschach test”, in which the inkblot takes on multiple meanings.

Enthusiasm, even if misdirected, is more alluring than bearing a grudge about someone else’s vision. Yet the tentacles of pessimism have spread much more broadly among liberals, who traditionally believed in harnessing the best of human endeavour. Liberalism acknowledges the continuing fight of individuals and society against overweening power or obscurantism, but it also needs determination and flexibility.

Does the language of centrist progressives still say this with any gusto? Or is it locked into predicting disasters? The overuse of “catastrophic” to describe a range of Brexit outcomes is followed by a new contender in the cliche charts – “deeply troubling” (in which the “deeply” bit means something happened that one had not predicted and is thus confused about).

If the BBC gets unfairly into hot water on charges of skewed impartiality, I might suggest to commissioners, including my beloved bosses at Radio 4, that the tone and range of ideas can tip too easily into “woe is us”. As much as we relish the Greta Thunberg blasts on climate warnings and lawyers giving stern takes on how democracies might perish, it does reflect a mindset captured by the Pet Shop Boys’ satirical Miserabilism: “Make sure you’re always frowning/ It shows the world that you’ve got substance and depth.”

Somehow, the Conservatives have acquired a key liberal trait and vice versa. Tories have long been aligned to a view of mankind with roots in stoicism and gradual change. Yet the leap to leave the EU was also a moment when headstrong instinct prevailed over caution.

Liberals (in the British tradition) flourished politically as the Whig party, embracing institutional and social reform. Even when they miscalculated or sometimes failed (as in the “liberal” interventions of the early 2000s), the guiding desire was to engage with an evolving world. This did not always make them right, but it did make them a force to be reckoned with in democracies and on the international stage.

Liberal Democrat leader Jo Swinson speaks after losing her East Dunbartonshire seat. Photograph: David Cheskin/Getty Images

These days, the general mode of communication is a miffed sense of being rejected, while telling everyone they were right all along and you will one day realise this. I keep thinking back to Jo Swinson’s election night speech, which wanted to tell us that she stood by an “open, welcoming, inclusive society” (so far, so good), but ended blaming “nationalism” for eviscerating her party, rather than a poorly thought through Brexit strategy. After a rollicking SNP defeat, we can forgive a bad note or two, but that sourness needs to be dealt with by her successors or anyone with an intention to revive a third force between the far poles of British politics.

Just telling voters that they are the dupes of some vague but regrettable force does not feel open about why the progressive project is struggling in Britain and beyond. Battered centrists, who exist across the parties and beyond them, will need to respond to a new political settlement. They may have to bite their tongues as the prime minister, seeing a changed Conservative landscape before him, boosts investment in the north of England and entrenches in political territories that the centre-left deemed, in the fond but patrician language of Blairism, “our people”.

The projected reopening of the Newcastle-Ashington-Blyth railway line to boost deprived towns isolated by poor infrastructure will serve as a symbolic moment for the Johnson re-engagement with northern lands (and a useful fillip for more devolution, since the idea was hatched locally, before the election).

Such prospects also offer openings for local people, since they demand attention to the kind of detail and practical decision-making that centrists have long cared about – how projects work in practice, the consequences and opportunities for communities and environmental protections. Decentralising will encourage fresh thinking about how to reboot sagging projects such as the city academies for areas outside the metropolis and strategies for public sector revival that go beyond raising spending levels. That is the kind of progress liberals should hold the government to delivering, when the honeymoon is over.

To recover relevance, liberalism needs to change the way it sounds and how it thinks about itself, to make the arguments that matter – on how societies heal and flourish, the balance of state and market, and the need to engage voters fully on climate change – without alienating them by preachiness. Too many of these arguments will go unheard if the overall tone is self-pity and Bregret. A Greek chorus telling us how awfully the national drama is going will not sell tickets to the great progressive revival.

Lesson one: cheer up a bit. Then figure out how to take on the battle of ideas that still counts.

• Anne McElvoy is senior editor at the Economist and presents Across the Red Lines on Radio 4