It would be a symbolic threshold, but he's not really as electable as Blair unless Labour wins the election.
I knew someone would say that
Yes, I take that on board absolutely.
My counter-argument would be that the context is wildly different now, and we can't have a full picture of what's going on with Labour without looking at what's going on elsewhere with the Tory vote. Their support is huge, and is benefiting from the collapse of UKIP. UKIP weren't a thing back in 97, and the political landscape looked a lot different to how it looks today.
UKIP voters aren't a single breed, but rather a collection of interests, some of whom (the largest constituency I think) will have been Tories in the past, some Labour, some non-voters, some floating voters, a handful from BNP and elsewhere. The move of that vote to the Tories, in part thanks to Brexit, and in part thanks to the image of the Labour party, plays a huge part in whether any Labour leader is 'electable' or not.
So it depends on what terms we're judging it. If it's in terms of straight like-for-like vote share then yes, he's electable because he's very nearly at the threshold Blair reached when he stormed to victory. That's a winning vote share in terms of support needed to win in a specific circumstance. But the circumstances are different at the moment, so the bar is moved - which isn't necessarily the fault of the Labour leader or the Labour platform but rather of wider political realities and the context of the shifting political landscape.
So, certainly it's a truism that if you don't get elected you're not electable in that instance, but that doesn't get to the nitty gritty of what's going on under the hood.
