THE biggest puzzle in British politics is why the Liberal Democrats are so feeble. Forty-eight per cent of Britons voted to remain in the European Union. Millions of people think that Theresa May is a discredited mediocrity and that Jeremy Corbyn, Labour’s leader, is a dangerous fantasist. And yet the only party that campaigned to keep Britain in the EU and that proudly stands for the “open and tolerant” centre against extremists on left and right can’t even muster 8% of the vote. What should be the vital centre has become a no-man’s-land, if not a killing field.

This newspaper endorsed the Lib Dems in the election in June, partly because the other two parties were so unappetising and partly in the hope that a Lib Dem revival would spark a more general realignment. But voters have not forgiven the party for joining the Conservatives in forming the coalition government of 2010-15. A former president of the Lib Dems once described his party as the “cockroach” of British politics, for its ability to survive. Yet the coalition was an industrial-strength cockroach killer. The Lib Dems went into the coalition with 23% of the vote and 57 seats. They came out with 7.9% of the vote and eight seats. They lost all but one of their MEPs and thousands of local councillors. The coalition forced them to sign up to a programme of austerity and higher university fees that was anathema to the party’s members, who are disproportionately employed in the public sector. Worse, raising fees meant breaking a manifesto pledge.

The party’s implosion after the coalition coincided with the opening up of its biggest opportunity in decades: the Brexit vote. Had the party entered the post-referendum world with 60 seats and a charismatic leader it would have had a chance of engineering the political realignment that it has always dreamed of. Instead it entered that world as a political husk. A party with eight MPs was not well positioned to attract voters who wanted to reverse the referendum. The Lib Dems are now in a classic cycle of decline, with a weak bench ensuring that they have weak leaders who fail to break through to voters.

Tim Farron, the party’s leader in 2015-17, was arguably the weakest head of any major political party since the second world war. A poll taken two weeks before the election found that half the electorate could not name him. The one thing he was known for was that he was an evangelical Christian who was uncomfortable about homosexuality and abortion. This reduced his appeal to the secular liberals who formed the core of the Remain vote. When it came to attracting the young, the Lib Dems might as well have chosen someone who went around proclaiming that beards and tattoos were outward displays of moral depravity.

Vince Cable, the party’s current leader, is in a different class from Mr Farron. He is by far the most intelligent of the three party leaders (which is not meant to be damning with faint praise). He is a technocrat with a wealth of experience in both the private sector (he was chief economist for Shell in 1995-97) and in government (he was business secretary in the coalition) and lots of ideas for fixing problems like intergenerational inequality. He is also a publicity hog: he appeared on “Strictly Come Dancing”, a popular TV show, and has just published a novel, “Open Arms”.

So Mr Cable will save his party from being ignored. But the other points on his CV may not work in his favour. Voters want moral purity rather than experience, particularly if that experience involves working for a giant oil company. They want magicians who can shake the money tree rather than economists who point out that money trees don’t exist. Mr Cable also has two big drawbacks. He is 74 years old. Admittedly this makes him only six years older than Labour’s leader, but Mr Corbyn is essentially a young idealist trapped in an ageing body. Mr Cable is also the man who, as business secretary, introduced the bill raising tuition fees. Videos of him making that speech in Parliament will kill any chances of the Lib Dems breaking through to the young.

Mr Cable is also confronted with two problems that his talents are unlikely to equal. The first is Labour’s resurgence. The party has all but locked up the youth vote with a combination of anti-austerity politics and vague idealism. It has built a fearsome campaign machine that threatens to destroy the Lib Dems’ established advantage as a campaigning force. Above all, it has succeeded brilliantly, if disgracefully, in preserving “strategic ambiguity” on the question of Brexit by sending reassuring signals to both Remainers (who might otherwise be attracted to the Lib Dems) and Leavers (who once abandoned Labour for the UK Independence Party). Labour is doing its best to complete the work of destruction that the Conservatives began when they seduced the Lib Dems into jumping into bed with them in 2010.

Stuck in the middle

The second is the party’s ancestral problem with its identity. The Lib Dems are as much a hotch-potch as a party. They have always been divided between classical liberals, who believe in free-market economics, and communitarians, who are motivated by local issues. (Mr Cable is at the liberal end of the spectrum.) They are split between anti-establishment types, who are voting for “none of the above”, and establishment types who think the Lib Dems represent good sense. The party of electoral reform has 100 members in the House of Lords compared with just 12 in the Commons. The party of the open economy has its strongest roots in the most isolated bits of the Celtic fringe, such as Cornwall.

The first rule of modern politics is that almost anything can happen. The two major parties are dicing with disaster, the Tories by tying their fate to Brexit and the Labour Party by embracing Corbynism. France’s Emmanuel Macron has proved that anti-establishment sentiment can be harnessed by the centre as well as the right and the left. But so far the Liberal Democrats show few signs that they possess either the ideas or the momentum to fill the void at the heart of British politics.

Economist.com/blogs/bagehot