The moment when Labour’s then-establishment realised that Jeremy Corbyn was certain to be elected Labour leader was when Sadiq Khan defeated Tessa Jowell and became Labour’s London mayoral candidate in 2015 – thanks the second preferences of supporters of Diane Abbott, who finished a strong third place.

Now former cabinet minister Liam Byrne has defeated Peter Lowe, the former leader of Dudley Council, and Salma Yaqoob, the preferred candidate of much of Labour’s new establishment, to become Labour’s mayoral candidate in the West Midlands combined authority. Does this similarly point to a victory for Keir Starmer over Rebecca Long-Bailey in the leadership election?

Well, no and yes. No, because what we’re not seeing here is a change in the attitudes and composition of the Labour membership. But yes: because the approach that Byrne took, and the actual reasons he won, speaks to why Starmer is highly likely to win the Labour leadership race.

Byrne won for a number of reasons, but one that cannot be overstressed is that he had the highest profile among Labour Party members: he has been an MP for a decade and a half and a near ever-present on the party’s frontbench since 2006. Labour activists know that they have a very, very tough fight on their hands against Andy Street, the Conservative incumbent, and that was a significant consideration in the minds of many. Rightly or wrongly, a similar calculation is driving many Labour members towards Starmer.

One of the many mistakes in analysing the Labour membership, both in a derogatory fashion by Corbynsceptics and in a triumphalist one by Corbynites, has been to see the average Labour member as ideologically committed or particularly cult-like. The average Labour member is not that ideological. They have a broad set of left-wing values, but they are not committed to any particular strand of Labour thought.

What many factional operatives across Labour saw as a weakness – that Byrne was a Blairite loyalist, who went on to become one of the most vocal supporters of Yvette Cooper, and then returned to the frontbench after the 2016 coup against Corbyn – several saw as a strength: “unity” and loyalty are highly praised among the rank and file. That, too, is a factor in Starmer’s popularity among the Labour grassroots.

But equally, Byrne had done the hard yards as far as convincing Labour’s membership that he was a committed left-winger, both through a long-running series of well-made videos for Facebook and Twitter campaigning against the welfare cuts and through his personal friendship with John McDonnell, whose endorsement he touted frequently in the campaign’s closing days.

And while Starmer will have to do without McDonnell’s endorsement, the success of that hard work will be a cause for optimism among Team Starmer that they, too, will be similarly rewarded for doing something very similar.