> The Danish left predicted (imo, correctly) that the issue would remain and get more salient due to external factors. Then they got on the right side of it.
I see that you added this. There's a lot going on. "External factors" sounds like fixed facts of the world. But as I pointed out above, Immigration into the UK is steeply down (1), but this is not your perception or many other perception of the topic. It's not driven by facts.
Would you describe a mega-rich person in the USA using their social platform to stoke racial hatred in the UK and promote conspiracy theories as "external factors", fixed facts of the world? (1)
The far right engages in endless grievances and stoking of culture wars. It's what they do, they are not going to be satisfied with a minor concession, they will just be emboldened instead. And win or lose, if they have to abandon the current grievance, they will find something else to turn into the next grievance. Facts are secondary to this.
The idea that a rational centre-left party can meaningfully "get on the right side" of this escalation - and do so by agreeing with the hate-mongers - is not just wrong, it's nonsensical. Again, Mr Starmer tried it and got nothing.
If you think that's the "right side" then what you want is a right-wing party, no centre-left party is ever going to be the one for you - and this is in common with most voters as I said above.
> The alternative approach is to hope the issue will reduce in salience.
Nope. As they say, "Hope is not a strategy". The right is not going to stop stoking culture wars, as as it works for them, it's their main weapon. This is not a thing that will "naturally" reduce in salience by itself, as it was a political choice in the first place.
1) https://www.trtworld.com/article/18192985
https://www.rollingstone.com/politics/politics-features/elon...