Across the English-speaking world, the left has a leadership problem. In Australia, Prime Minister Tony Abbott’s unpopularity is exceeded only by that of Labour opposition leader Bill Shorten.

New Zealand’s conservative Prime Minister John Key is at a low ebb, yet he is still three times as popular as Labour’s Andrew Little. And in Canada, Liberal leader Justin Trudeau has tumbled to third place in the current election campaign, and looks like losing a race he used to lead.

But nowhere is the leadership problem more obvious than in Britain and the USA. In the UK, a recent poll found that 31 per cent of Labour supporters don’t back any of the leadership contenders, or don’t know which one they prefer.

A further six per cent prefer “Stewart Lewis,” a fake name that the pollster added to see if voters were paying attention. Evidently many are not: an additional nine per cent back Jeremy Corbyn, who hasn’t yet realised that Labour lost the 1983 election.

But the situation in the USA is worse. After Barack Obama, the US’s leading liberal might be Vice President Joe Biden, a man who crashed out of the 1988 presidential campaign after he was caught plagiarising speeches from Neil Kinnock. Biden is now a 72-year-old.

Or, the leading liberal might be Hillary Clinton. She’s 67. Elizabeth Warren, the progressive Senator from Massachusetts, is 65. Nancy Pelosi, the former speaker of the House, is 75. Jerry Brown, the governor of California, is 77. Bernie Sanders, the socialist Senator from Vermont who is challenging Clinton, is 73.

Now, being a pensioner doesn’t mean you’re useless: Reagan was 69 when he was inaugurated in 1981. But Reagan faced a tough Republican primary field that included future President George H.W. Bush, and Senators Bob Dole and Howard Baker, both in their 50s.

By contrast, it’s difficult to look around America, or Britain, and see the next generation of liberal leaders. Undoubtedly, this is partly cyclical: in the mid-1990s, the Tories were short on talent, yet a decade later, it was Labour that was exhausted. Liberalism is not down forever.

But the weakness of the liberal field today is remarkable. In Britain, Liz Kendall is the only “Blairite” candidate: The fact that the Labour Party still defines looking to the future in terms of Tony Blair, who left office almost a decade ago, illustrates the problem.

Liberalism’s weakness is also partly a numbers game: in the US, there are 45 Democratic senators and only 18 Democratic governors. Few are plausible contenders in 2016. If you want to know why Clinton is the presumptive favourite for the Democratic nomination, look at the weakness of her Democratic opposition.

In Britain, the left has an analogous problem. Labour is competitive in local councils – with 7,100 councillors to 8,300 for the Tories – but its MPs tend to be drawn from a pool of career politicians and trade unionists.

There’s nothing magical about private sector experience that naturally makes you a successful politician. Business is good at business, not necessarily at governing. But the range of talent from which Labour selects is remarkably narrow: it’s not surprising that its results are meagre.

But the core problem of the left is that its ideas are, in their way, too conservative – in the sense of offering the same old nostrums. At the last election, Labour opposed an EU referendum and free schools, and was deeply sceptical about Universal Credit and the common sense idea that Britain should live within its means. It had learned nothing, and forgotten nothing.

Much the same is true in Washington. In retrospect, Obama’s greatest triumph will be that he managed to make his tired ideas seem new. More borrowing, more welfare and more rules: that’s Vietnam War-era stuff. And, of course, Obama offered a “national conversation” on race. That was a clever phrase when Bill Clinton came up with it in 1997, but the US is now so exquisitely sensitive about race that it is impossible to discuss it at all.

We don’t need more conversations about race, which only makes us more conscious of differences that shouldn’t matter in a free society. We don’t need the Western democracies to make way for autocracies. And we certainly don’t need more borrowing, paid for by the shrinking younger generations.

If you want to lead, you have to have a destination in mind. And for that to happen, the left needs to figure out what being left means in a globalised, post-industrial, heavily indebted, and low- birthrate world.

That’s not a world where yesterday’s answers are going to work. When the left learns that, it will find its leaders. Until then, it will have Bernie Sanders, Jeremy Corbyn – and Stewart Lewis.

 - Ted R. Bromund is a senior research fellow in Anglo-American Relations, based at The Margaret Thatcher Center for Freedom at The Heritage Foundation in Washington.