Anecdote masquerading as data alert.
We had dinner with a couple we've known for 25 years, who live in the constituency. They are third sector workers (different NGOs), he's from Bristol, she's from Aberdeen. Progressive, arty, literate, follow the news. Originally long term Labour voters (not members). Voted No in Indy ref. Suddenly switched to SNP at the following GE for reasons I never pinned down. Voted Remain in Brexit ref. Then became independence supporters, mainly due to Brexit and Boris.
They are now very disillusioned with the SNP, and politicians in general. They won't vote SNP in by election. They said they obviously won't vote Tory, they said they can't vote Labour because of Starmer, who has shocked them on immigration and the climate, they think voting Green is statistically a waste of time, and they just laughed when I mentioned the Lib Dems.
Now, in the past they've had a go at me for not voting. "People fought for your right" "you can't complain if you don't vote" that sort of thing. But they are now thoroughly disillusioned and can't see how they would vote.
I know this is just one couple, but I suspect them of being indicative of a cohort in the population. Broadly "liberal" broadsheet readers who were won over by Sturgeon but who are now just disgusted with politics.
I think the "middle class" vote might have a low turn out in this by election.
Oh noes!
Now that I’ve had a nap and re-read it I’m regretting my rashness! 
