Almost a year ago, Nick Clegg led Britain’s Liberal Democrats into government for the first time in two generations, in coalition with David Cameron’s Conservatives. It was part of a period that recorded striking gains for liberal parties across the world, in countries as far removed as Japan, Germany, Poland and the Netherlands.

Today the view is much less rosy. The biggest of the concessions Clegg won from the Tories, a referendum on a move to preferential voting (the “alternative vote”, or AV), has come to nought, with the vote today going against the change — according to the unanimous verdict of the opinion polls (proper counting will not take place until tomorrow) — by a margin approaching two to one.

In local elections across the UK it’s a similar story: the Lib-Dems are losing ground across the board, from some combination of dissatisfaction with the coalition’s record and opposition among their grassroots to the very idea of joining with the Conservatives in the first place.

And this comes on top of Monday’s election in Canada, where the Liberal Party — the traditional party of government, and probably the most successful of the liberal family in the world — recorded its worst ever result, falling to third place with just 18.9% of the vote. While the Liberals can’t be written off, since Canada’s Conservatives recovered from a much worse result in the 1990s, it’s an ominous sign for liberal parties everywhere.

Australia’s Liberal Party, by contrast, has no such problems, scoring big swings in its favour in every election, state or federal, in the past three years. But its similarity with the Lib-Dems or the Canadian Liberals pretty much ends with the name: unlike them, it lines up not with Liberal International, the world organisation of liberal and progressive democratic parties, but with the conservative and centre-right parties grouped in the International Democrat Union.

So what looked like a movement towards the liberal free-market end of the political spectrum has run into trouble. Is this a general trend, or a phenomenon limited to two countries in the anglosphere for their own particular reasons?

Pundits love simplicity, and in Britain and Australia it’s common to present the spectrum as a one-dimensional affair based on economic policy: free marketeers and pro-business interventionists on the right, big government supporters and friends of the toiling masses on the left, and the rest arrayed somewhere in the middle.

On this basis, liberal parties defy easy classification because their economic views vary considerably: the Lib-Dems range from the pro-market “orange book” group to a much more interventionist activist base that see themselves as to the left of Labour. The values that mark them as distinctive are not primarily economic: they’re about giving priority to the freedom of the individual and the values of an open and democratic society.

Those things are important. In the long run I think they matter much more than a percentage point more or less on the tax rate. But it can’t be denied that in the past couple of years economic issues have pushed their way to the fore, and that’s made life especially difficult for a liberal party that has a junior place in government, like the Lib-Dems. Its members end up having to wear the unpopularity of their senior partner’s policies and their own indecisiveness.

Nonetheless, Britain’s coalition is only a year into a five-year term; a lot can happen between now and when the electorate will get to pass its considered judgment. Local polls, despite the avid attention they are given in the media, have a very poor record as a predictor of the following election.

And it remains true that Clegg’s options last year were severely limited, and that many of those who criticise the decision to work with the Tories are less than clear about what the Lib-Dems could have done instead. For them to have forced a new election — still an option, of course — would almost certainly have annoyed the electorate more than anything they have done in government.

Tonight’s results have clearly weakened Clegg, and increased the chance that at some point his party may turn to a less Tory-friendly leader — probably energy secretary Chris Huhne. But that won’t change the fundamental dynamic, that the Lib-Dems need to demonstrate flexibility between the two big parties, but not to the extent of appearing unprincipled or promoting instability.

It’s a difficult task, but one that third parties everywhere (compare the Australian Greens) have to somehow learn to deal with.