Since it became clear yesterday morning that the pro-independence majority in the new Scottish Parliament would be dependent on two parties and not just the SNP alone, a debate has raged over whether this has significantly reduced the chances of a second referendum during the next five years if one of the fabled 'material changes in circumstances' occurs (the most likely of which is Brexit). My own view is that it hasn't, for the reasons set out in my IBTimes piece. However, I do accept that my assessment can only be a provisional one at this early stage, not least because I'm not an expert on the internal politics of the Green party, upon which so much now depends. I certainly think that a little heat should be put on those Green members and sympathisers who effectively authored this suboptimal election result by duping people into thinking that SNP list votes would be "wasted", and definitely wouldn't be needed for an overall majority, etc, etc. The least they should be doing now is setting some minds at rest about the Greens' stance on a second referendum.
However, there's one very simple way of looking at this problem that doesn't actually require a nuanced understanding of Green attitudes. Let's take a close look at the composition of the new parliament...
Liberal Democrats 5
(As an aside, it really should be noted what a truly dreadful outcome that is for the Liberal Democrats, who suffered an exact repeat of their catastrophic result from 2011 in spite of having been relieved of their toxic ties to the Tories. Why Tim Farron and Willie Rennie were hugging each other and cracking open the champagne is anyone's guess.)
Now, just for a moment, let's remove the Greens from the equation altogether, and see what's left...
Unionist Parties 60
As you can see, the SNP in their own right clearly outnumber all of the unionist MSPs. But why does this matter, given that the Greens obviously do exist and do have six votes that could theoretically swing the balance in either direction? Well, because in any parliamentary vote, there are three options open to any MSP - they can vote in favour, vote against, or abstain. (The latter option is colloquially known as "doing a Labour".) So if, for the sake of argument, the UK voted to leave the EU next month, and the SNP responded by tabling some sort of proposal for a second independence referendum, the only way it could be voted down would be if the Greens actively voted against it. If they merely abstained, the referendum proposal would be passed by 63 votes to 60 (or in practice by either 62 to 60, or 63 to 59, depending on whether the new Presiding Officer is a government or opposition MSP).
Therefore, if you really think that the chances of a second indyref have been substantially diminished, it follows that you must also believe that Patrick Harvie and his troops would actively vote it down on the floor of the Scottish Parliament. Is that a remotely credible belief? Apart from anything else, it would be electoral suicide for them, as so much of their new support was directly won as a result of their pro-independence stance. Even if they had severe misgivings about the specifics of what the SNP were doing, they would surely be more likely to abstain and allow the proposal to pass without taking direct responsibility for it.
Now, of course I can't be 100% sure of that. I was astonished last summer when Caroline Lucas actively voted against Full Fiscal Autonomy in the Commons, and said afterwards that she only did so in deference to her Scottish colleagues' express wishes. That incident didn't lead to any great internal dissent within the Scottish Greens, or not that I noticed anyway. But I really think that actively voting down an independence referendum would be in a different category entirely - they would lose a huge chunk of their membership and support, and I simply don't believe they would do it.
So in my view, the parliamentary numbers are there for a second referendum if the SNP decide to pull the trigger. That's only half the battle, of course. If they were aiming to bypass the Westminster veto altogether by holding a consultative referendum, they would need the Presiding Officer to certify the legislation as being within the parliament's powers. That gives the SNP a big dilemma right now over who to install as the new Presiding Officer. For obvious reasons, they don't want it to be someone like Adam "IT'S THE LAW!!!!" Tomkins, but neither will they be very keen on giving up one of their own MSPs when the arithmetic is so tight. Ideally, what they could do with would be the equivalent of a John Bercow, who was nominally a Tory but very friendly towards Labour. I'm not really sure whether such a person exists, though, so they may have to decide upon the lesser of two evils.
If, on the other hand, the SNP seek a repeat of the Edinburgh Agreement, they would need the Westminster government to respect the mandate for a second referendum. Some would argue that the result on Thursday makes that less likely. But here's the thing - a "mandate for a referendum" is not a concept with any legal or constitutional standing whatsoever. The London establishment are literally making up the rules on this as they go on, and if they had been facing an SNP majority government, they would simply have reverted to the alternative excuse that the wording of the manifesto wasn't clear enough. So yes, they might now say "you don't have a mandate for a referendum because the SNP didn't win an absolute majority", but that's nothing more than a debating point, and the SNP have the obvious replies of "the pro-independence parties do have an absolute majority" and "we won a vote to do this in the democratically-elected Scottish Parliament". The outcome of any dispute along those lines would probably depend to a large extent on the public mood at the time. If it was clear that Westminster resistance to a referendum was creating a backlash against London rule, Cameron or his successor might be forced to the negotiating table.