Everyone knows your eyes can lie, that the evidence you see around you can give a false impression of what’s really going on, and it was like that in Glasgow in 2014. I remember walking about the city on the day of the referendum and every second person, it seemed, was wearing a Yes badge or waving a paper saltire. I remember the feeling I had: Yes has won.

I was wrong, of course: the atmosphere in Glasgow may have reflected how much of the city was feeling, and the way that many of its residents would vote – some 53% of voters in the city supported Yes – but the flags and the badges gave a misleading impression of the national mood. I remember sitting in my flat in Glasgow and hearing whoops and cheers and screams from the flats around me when Yes briefly nudged ahead, then a kind of chilly silence when No took the lead again and went on to win.

In some ways, Glasgow’s enthusiasm for Yes seemed like a bit of a surprise. You may remember a well-known blogger, before the referendum, calling Glasgow “the heart of unionist darkness” and “the Union’s citadel of power”. He based this assertion on the fact that the city was then dominated by Labour, and in some parts by traditional unionist loyalties, and even now I can see why he believed it. Stroll down Paisley Road West this afternoon and you’ll see the red sandstone reflected in red, white and blue.

These pockets of unionism are obviously still strong – Yes won in Glasgow by 7% remember – but Yes and the SNP has become the majority for the same reason that Labour used to be the majority. Glasgow has its unfair share of poverty and deprivation and so is likely to favour the party that promises change (even if they never actually deliver it). Far from being the heart of unionist darkness, Glasgow, along with Dundee, is the capital of Yes.

However, with another referendum probably (not) happening next year, it’s interesting to ask whether Glasgow as a citadel of Yes might be a problem. I was speaking the other day to Roza Salih, the remarkable young activist who became famous as one of the Glasgow Girls and has now been elected as an SNP councillor for Greater Pollok. Ms Salih, who was born in Kurdistan, has made Glasgow her home for the last 20 years but she also believes that the city could be a problem in any future campaign.

Her logic is essentially this: the Yes campaign did well in Glasgow but nationally it lost the campaign and that’s a problem that needs to be addressed. If there is to be another referendum, she says, the campaign will have to be much better organised and that means focusing on cities other than Glasgow. She feels the 2014 campaign was very Glasgow-centric and that it will have to be different next time. We should focus on cities instead of Glasgow, she says.

One of the cities she has in mind is my home town: Aberdeen, although I have to say I didn’t entirely recognise Ms Salih’s characterisation of the place. Aberdeen, she told me, is mostly rich people, thanks to oil, and rich people like the revenues. “The mindset is very capitalist,” she said, “and the way they’re thinking is ‘I’m good, why should I vote for Yes? I have a good earning, I’m rich, this is not good for me, I’ll be voting No’.”

If we accept Ms Salih’s premise – and it’s certainly true that the better off you are, the less likely you are on the whole to vote Yes – the obvious next question is how you convince well-off people in Aberdeen, or anywhere else for that matter, to convert from No. And this, I think, is where the SNP argument comes up against the same old problems. They will raise sceptical eyebrows in Aberdeen, believe me.

Ms Salih’s argument is that the SNP must make the case for the economic benefits of independence but also the economic and political weaknesses that exist in the UK as it stands and she singles out, with considerable justification, Brexit as an example. “The problem the Scottish people have,” she told me, “is this fear of becoming independent. But what is the fear now? Workers’ rights are under attack. We’ve been taken out of Europe. There’s fuel poverty and a crisis of poverty. What could be worse?”

There will be people, even well-off people in the nice granite suburbs of Aberdeen, who will get that argument and it’s one of the reasons the SNP, in private, would have preferred Boris Johnson to stay on and keep on giving. But it’s when the arguments turn to the potential benefits of independence that we have the same old questions, in Glasgow, Aberdeen, or anywhere else. Ms Salih says the oil price has recovered. She also says Scots will get their share of their pensions and there won’t be an issue at the border. The problem is: I’m not sure I believe her.

In a way, this is the Glasgow problem that the Yes campaign has. As far as I can see, it has largely won its case in Glasgow and Dundee and in places where there is a higher than average degree of deprivation. It may also explain why they are ahead with young people because young people have less money and, to them, pensions are theoretical things that don’t matter yet. They have nothing to lose so what the heck.

However, the problem for the Yes campaign is that Glasgow, and Dundee, and young people, represent only certain aspects of Scotland. Remember that in Aberdeen only 40% voted Yes. In Edinburgh it was even lower at 38%. Perth: 39. Stirling: 40. These are the cities that Roza Salih would like the SNP to focus on if there is another referendum and to an extent she’s right. If you don’t win over Edinburgh, Aberdeen and Perth, you’re not very likely to win the vote.

The question is though: even if the SNP were to relentlessly focus on the cities that said No, as Ms Salih would like, there isn’t much evidence that the party has the arguments that will make the cities say Yes. Every time I go back to my home town, it strikes me how much I have become used to Glasgow and the way many Glaswegians think. It can give you a false impression of the rest of Scotland. You can be blinded by the Yes badges and the flags. But Glasgow is not the whole story. Glasgow is not the whole of Scotland.

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