NICK CLEGG has endured diverse insults during his two years as deputy prime minister. But the latest slur, carrying a suggestion of physical cowardice, is new. Mr Clegg was asked on a radio show what he would have done to defend a celebrity chef, Nigella Lawson, who had been snapped by a paparazzo being manhandled by her husband in a restaurant. He replied that, without knowing what had really transpired, he could not say.

That was reasonable; for Mr Clegg’s opponents it was evidence of the spinelessness of which the Liberal Democrat leader is often accused. Ed Miliband, leader of the Labour Party and not a natural vigilante, declared that unlike the feeble Lib Dem he would have intervened in Ms Lawson’s defence.

This was revealing nonsense. It suggests how far off is the grown-up, pluralist politics Mr Clegg advocates. It also hints at how damaged he and his party have been by their first experience of government in decades. Mr Clegg is Westminster roadkill; his net personal approval rating is minus 52. Having won 23% of the national vote—and 57 seats—in the 2010 election, his party is scarcely doing better. The latest poll from YouGov puts it on 11%, level pegging with the populist UK Independence Party (UKIP).

This is a dramatic collapse. But it is also misleading. The Lib Dems are at once enfeebled and remarkably strong. Indeed, it seems increasing likely that they and their rubbished leader will decide who rules Britain for the foreseeable future.

The main reason is that voters do not think much of their main opponents, Labour and the Conservatives, either. This was a big factor in the Lib Dems’ erstwhile appeal; roughly a third of the party’s votes were cast in protest against mainstream politics and another third by centrists who hated the Tories. Coalition government with the Conservatives has eroded that chunk of the Lib Dems’ support. And in those of its seats (roughly a third of the total) where Labour is its main rival, the party faces a walloping at the next election, due in 2015. But elsewhere it may stand firm.

It is losing votes to UKIP and the non-voting ether; but hardly to the Tories. This was evident in a by-election in the Hampshire seat of Eastleigh in February, which the Lib Dems won after UKIP and the Tories split the right-wing vote in two. The Lib Dems will hope to pick up a few more such seats from the Tories in 2015, in places where they and UKIP are both strong. Despite their wretched polling, they can thereby expect to get between 30 and 40 seats in 2015. And that may well be enough to make Mr Clegg the kingmaker again, so fractured is the national vote becoming. In 1951 the Tories and Labour together won 98% of the vote. In 2010 they won 65% and neither could win a majority in Parliament. Current polling suggests a similar result is likely next time around, with the Tories extremely hard-pressed to build a majority and Labour only a bit likelier.

A steely optimism pervades the Lib Dems, most obviously among Mr Clegg and his fellow centrists. There are not many of them in a party whose ranks are well-stocked with a type of middle-class lefty, at once high-minded and determinedly parochial. During the opposition years these foot-soldiers kept the Lib Dems (and their forebear, the Liberal Party) alive in a south-western and northern range roughly analogous to the last redoubt of the endangered red squirrel. Having no prospect of power, the party existed as a motley of local campaigns, enlivened by national policies that were Utopian, spendthrift and sometimes—as per an ambition to ban goldfish from fairgrounds—a bit weird.

Mr Clegg has improved matters. He has insisted that the party’s policies should be liberal and affordable. On June 22nd he declared that the Lib Dems now face a big decision. They can cement that shift, becoming a “fully fledged party of government”, or return to left-wing protest and the “comfort blanket of opposition”. No prizes (including goldfish) for guessing which Mr Clegg chooses, and he can be fairly sure of getting his way. He is in little danger of a leadership challenge—his main rival, Chris Huhne, has been jailed for dishonesty over a driving offence.

Super furry animals

He has hired a highly rated South African strategist, Ryan Coetzee, to chart a national course. Mr Coetzee reckons the potential Lib Dem share of the vote—or “market”, as he calls it—is undiminished, at around a quarter of the total. To appeal to these voters, many of whom have yet to discover their inner liberalism, the party is doing two things. It is increasingly looking to claim successes of the coalition government as its own: for example, a scheme to provide more money to schools with poor children. More broadly, it is looking for ways to burnish the reputation of coalition as a method of rule. The idea, hitherto untested on voters, is to show that the Lib Dems are less a makeweight, in the event that the bigger parties fail to get a majority, than an improving influence on them both—with the power to offset Tory austerity with care for the needy and Labour profligacy with a tight fiscal grip. At the least, this ensures there will be no ugly and precipitate break-up of the coalition at the Lib Dems’ hands.

Yet there are snags. One is that the lefties may become noisier as the election looms. Another is that most Tories, partly as a projection of their own divisions, are vehemently against the coalition; though David Cameron, the Tory prime minister, is not. The party may therefore refuse to entertain a rerun afterwards, even if that is its way to power. Labour is also wary. Its members are reluctant to share ground with Lib Dem lefties, yet consider Mr Clegg too right-wing. Mr Miliband and Mr Clegg are not close.

This promises lots more rancour, Westminster style. But it will not curb the rise of coalition politics, as the British electorate becomes more splintered, as most continental European ones are. And the Lib Dems, however reviled they may be, are determined to profit from that. Having tasted power once in a lifetime, they want more of it.

Economist.com/blogs/bagehot