THE story passed down about my Gran Kane was that she snarled at the mention of Winston Churchill.

One of her Irish family was murdered by a member of the Black and Tans, a regiment Churchill formed when he was British secretary of war in 1919. Recruited largely from shell-shocked Great War soldiers, the Black and Tans struck terror into rebellious Nationalist communities in the North of Ireland.

So even before I became a perfidious independista, inherently sceptical of the call to “Great British” anything, we had a familial line on the great war hero Winston Churchill.

Churchill is currently serving as an artillery barrage in the culture wars over Brexit. This week’s mass harrumphing stems from an incident that also sits in the foothills of Churchill’s biography.

The Labour shadow chancellor John McDonnell answered a villain/hero question on Churchill with the words: “Villain – Tonypandy”. Tonypandy was another occasion – in 1911, prior to the Black and Tans – where Churchill (then home secretary) sent in the troops to help quell civil unrest on British soil. This time against Welsh miners, striking for better conditions.

McDonnell is receiving the same pelters – from the same sources – as the Scottish Green MSP Ross Greer did a few weeks ago. Greer had pointed out Churchill’s white supremacist beliefs in the “Aryan race” (and the inferiority of other races), and his conscious starvation of Bengalis during the Second World War.

The biographies clearly show that Churchill’s finest hour was one where the extremes of the moment happened to require a man of his particular make-up. Churchill’s constant desire was to defend the British Empire, because he believed in the improving and civilising effect it had on its subjects.

He was kept at a distance by fellow Tories during the 1930s, where his virulent and racialised opposition to Indian independence offended many. Yet Churchill’s enthusiasm for war – both as a soldier and politician – seems to have been the crucial factor in his decision to refuse a “European Settlement” (such a curious, contemporary phrase) with Germany in May 1940, and continue fighting the Nazis.

As Prime Minister, he defied appeasers like Lord Halifax and Neville Chamberlain, and was supported by Labour’s Clement Attlee as part of his War Cabinet.

Churchill has a sprawling, complex biography. But I am fascinated by how this is all reduced to these crucial years of decisiveness, at the heart of the Allied war effort.

This is not just about Brexiteers trying to appropriate him for Brexit. (Which is, in any case, quite hard to do. Churchill was a very early advocate – in 1946 – for a post-war “United States of Europe”, and the “re-creation of the European family”).

Indeed, Churchill does quite a few ideological cartwheels in his life.

The early Liberal Churchill, conspiring with Lloyd George to begin a minimal welfare state, is not often remembered.

But it’s as if Churchill, in his crucial war years, answers the question for many, when they ask: “what is leadership?”

Someone who breaks with conventional wisdom, and sees the crisis for what it is? Someone who can construct and deliver a story of action about that crisis, which mobilises a public majority? Someone who can enlist reluctant colleagues and peers, in order to put their talents and skills to a cause?

A thought to cheer you up on a Saturday morning: how poorly the Churchill-wannabe Boris Johnson measures up to this.

Though perhaps Boris’s mediocrity matches the mediocrity of the moment. Brexit will probably be only a mild degrading of the existing trade and legal relationship with Europe, a milquetoast answer to an anti-elitist spasm in the south of England. Maybe it only requires hype-merchants and grey bureaucrats.

Facing down Nazi Germany, and its demands for “lebensraum” and “reich”, might have been a little more existential a challenge.

Yet I just can’t agree that Churchill represents some ideal of leadership that’s still relevant to 2019. If you listen to the speeches again – a Radio 4 show called Churchill’s Roar sets them up beautifully online – the growling, slurring rhetorician coming at you seems near ludicrous.

For one thing, Churchill is like a cartoon version of the aristocratic upper-classes. It’s also absurdly, almost camply patriarchal. Locked in a grip with his even more excessive enemy, it’s the sound of male power, getting ready to chuck even more males (and death-tech) at each other. It feels not just from another era, but from a parallel universe.

When the bloviating Piers Morgan screeches at the well-scrubbed Ross Greer that (among other epithets) “you’d be speaking German right now if it wasn’t for Winston Churchill”, we’re watching quite a spectacle.

On one side, here’s a baby-boomer lost in self-loathing, thinking himself a mere shadow of his fathers’ “Greatest Generation”. On the other side, here’s a Generation Z’er, who assumes that normal life means living in complex, creative and peaceful relationships (human or digital) with others. Someone who can also find information about anyone, challenging the conventional wisdom of mainstream media gatekeepers.

The gulf is huge. For the Gen Zs (who may need to become, as my partner Indra Adnan has quipped, the ReGen As), the ideal figure of action is the shining teenager Greta Thunberg. Her weekly eco-protest in front of the Swedish parliament has triggered a global wave of school-strikes.

Or take Alexandria Ocasio-Cortez, who gets elected to Congress and then makes herself a conduit for a whole range of suppressed policy alternatives in America.

These leaders play across our expanded mediascape with ingenuity and focus. They aim to trigger actions and commitments whereever people are located – they don’t wait to recruit them to the party first. This is power flowing across boundaries, inspiring activism everywhere, mostly aimed at saving a planet – not defending an empire.

Yet for the older demographic (a strong predictor of a Leave vote, let along a Scottish No vote), the single-minded heroism of a Churchill represents a rebuke to, or a retreat from, the fluid field of Gen Z’s politics.

The boomers might say: your identity politics, your digital transformations, your banal cosmopolitanism – that’s all well and good.

But we remember a time, or more likely, we honour our parents’ memories of a time – when evil had to be opposed; when national unity was vital and necessary; when clarity and bravery were required. In a confusing era, this is an understandable reaction.

There’s a modern irony here. As many green thinkers say, the terrifying urgency of climate disruption demands a systemic shift comparable to a full-on war effort, in its speed and scale. But ask yourself: does it also really require a Churchill-like figure to win that war?

Certainly, one minimal demand of leadership in any era might be that you are prepared to “walk the talk”, manifesting your consistency and integrity. My family history remembers Churchill bitterly, in his troops-happy, war-mongering mode. However, this predominant characteristic came to have its uses, eventually.

So will the leaders we celebrate in 50 years be those who followed in the footsteps of Greta Thunberg? That is, those who simply put themselves at the heart of existing, toxic power; who spoke the clear truths of planetary meltdown to leaders; and who personally embodied the changes they wished to see?

Perhaps the Gandhi who Churchill had such contempt for, as he sought to prevent Indian national liberation, will have the very last historical laugh.