This has only just occurred to me, but it should have occurred to me a couple of weeks ago. What do we know, or think we know, about the seven Scottish Labour seats at Westminster? That six of them would be under severe threat if there is a swing to the SNP at the next general election, but that the seventh (Ian Murray's constituency of Edinburgh South) is absolutely rock-solid in almost all circumstances. But, as it happens, Ian Murray is also the only one of the seven MPs to have been dropping hints about the possibility of defecting to the Independent Group. And it's not even irrational for him to have done so. For almost any other Labour elected representative in Scotland, it would be electoral suicide to join TIG, because the traditional Labour vote would not follow them across. But Murray doesn't primarily owe his position to the traditional Labour vote, but rather to industrial-scale anti-SNP tactical voting, and those voters would in all likelihood see Murray under any party label as the best prospect for keeping the SNP out. At the very least the odds would be against Labour holding Edinburgh South if Murray is standing against them - if we're being super-optimistic, there's a chance that he might split the unionist vote and let the SNP in through the middle, but more likely is that he'd retain the seat himself.
So if Murray defects, it could be a double-whammy - it would generate anti-Labour momentum that might make it even more likely that the other six seats will fall, while also depriving Labour of the one seat they thought they could bank on. But even if they were completely wiped out in Westminster, would it actually matter in the long-run? After all, the Scottish Tories were wiped out in 1997, but regained a toe-hold in 2001 and then eventually came back with a vengeance in 2017. Perhaps the difference is that the Tory core vote had nowhere else to go (or nowhere credible) even when the game seemed to be up, whereas there are a great many alternative homes for hitherto committed Labour supporters - if they're pro-indy, there's the SNP, if they're socially liberal, there's the Lib Dems, if they're dogmatic unionists, there's the Tories, and if all else fails there's the Independent Group itself. Voters might just take a signal from a wipeout in the Commons that would lead to a total and irreversible collapse of the Scottish Labour vote. I'm not making a prediction, but it's a plausible possibility.
Having said all that, Murray might be given pause for thought by the latest Opinium poll including the Independent Group as an option on a standard voting intention question. Opinium are the only polling firm to be taking that approach, and it's unsurprising that they're producing much lower numbers for the Independent Group than firms who ask hypothetical questions that make a song and dance of reminding respondents about the group's existence.
Britain-wide voting intentions including the Independent Group (Opinium):
Conservatives 37% (-3)
Labour 33% (+1)
UKIP 7% (n/c)
Liberal Democrats 7% (+2)
Independent Group 5% (-1)
SNP 4% (n/c)
Greens 4% (n/c)
Plaid Cymru 1% (n/c)
Scottish subsample: SNP 44%, Labour 25%, Conservatives 23%, UKIP 3%, Greens 1%, Independent Group 1%, Liberal Democrats 1%
That's probably the most reliable guide we have to the Independent Group's true popularity at present, and it's not hard to see how it could deter further defections. And yet, ironically, the only way the group are likely to improve their standing is by attracting a lot more defectors.
There's a famous quote attributed to Peter Hitchens that always does the rounds when an opinion poll that people don't like the results of is published: "Opinion polls are a device for influencing public opinion, not a device for measuring it. Crack that, and it all makes sense." Of course that's not true, or at least it's not the whole truth - opinion polling is a spectrum, with cynical American-style push-polling at one extreme, polls produced with the honest intention of discovering the current state of play at the other extreme, and all sorts of shades of grey in between. But what we're living through at the moment is a clear-cut example of a scenario in which decisions made by pollsters and those who commission polls are likely to shape the outcome of future elections. There's a clear incentive for those sympathetic to the Independent Group to downplay the credible Opinium results and instead commission (or talk up) more of the fantasy polls that purport to put their heroes in the teens or even higher. As misleading as those polls are, they could prove to be a self-fulfilling prophecy if they hoodwink potential defectors into thinking they would be joining a party that is already a going concern.
There's a sub-plot here, though, because Heidi Allen has told ITV in a new interview that the Independent Group are actually trying to discourage any more than two or three Tory MPs from defecting for the time being, because that would "destabilise the government". As bonkers as that may sound, you can kind of see her point - even if a much-expanded Independent Group abstain on confidence motions, the likelihood is that a Conservative-DUP alliance without a working majority would not be able to plough on, and a snap election would see the Independent Group project snuffed out before it really got started. And yet if the Independent Group limit their own critical mass in the Commons, they'll make a breakthrough less likely anyway. It's a real Catch 22 for them - it's certainly hard to see how they'll overtake the SNP as the third largest group in the Commons without a decent number of Tory defectors.