Just how solid is Scottish Labour's list vote?

Amid all the process and horse race stuff in this Holyrood election, there is one rather important question going conspicuously unasked: just how solid is Scottish Labour's list vote anyway? 

All the mischief has focused on the loyalty of folk likely to vote SNP in the constituencies. Will they stick with "Nicola Sturgeon for First Minister", or split their tickets, lending support to some other party for the regional calculation? This is all well and good. But the endless, circular conversation about the virtues and vices of #BothVotesSNP overlooks the fact that it is Kezia Dugdale's party whose fate will largely be determined by the d'Hondt calculations and the weight of support she can command on the regional ballot. 

And Scotland's electoral history being what it is, I wonder if Scottish Labour aren't more vulnerable to - potentially catastrophic - leakage in regional support than we've generally noticed. As countless commentators have pointed out, for years, in the wake of devolution, Labour didn't have a second vote strategy - they didn't need a second vote strategy - being comfortably returned to office on the back of the first-past-the-post constituencies and their reliable confrères, the Liberal Democrats.  

In this model, if Scottish Labour's electoral fortunes were to improve, you'd expect this to express itself in constituency gains rather than regional progress. But if the Holyrood map broadly follows Westminster's this election, the whole basis of Labour support will have been rearranged on a regional basis. In fairness, Scottish Labour are pushing their own #BothVotesLabour message. I'm sure old time Labour supporters who have stuck with the party will heed this and maintain a disciplined ticket. But the party aren't going great guns with the message. Which seems a decidedly strange thing, considering how critical a solid, loyal regional ballot is for the party's standing in the next parliament. 

Look at this historically. Take 2011. Alex Salmond's SNP secured 902,915 constituency ballots, and 876,421 in the regions. We shouldn't understand this as a straightforward 26,494 drop. The regional tally will include a decent whack of folk who voted for other parties in constituency contests. My favourite 2011 illustration of this dynamic was Ayr. A straightforward SNP vs Tory runoff, Conservative candidate John Scott secured 12,997 constituency votes, and a 1,113 vote majority over his SNP opponent. But in the region, the folk of Ayr gave the Tories only 8,539 votes, a drop of 4,458 on their constituency figures - and the SNP were the obvious beneficiaries of the Tory regional slump. Chic Brodie took 11,884 constituency votes, but Ayr's regional tally gave the Nats 14,377, an increase of 2,493 which put them 5,838 regional votes ahead of the Tories who'd routed their constituency campaign.  

So what about Labour? In 2011, Iain Gray took 630,461 constituency papers and just 523,559, losing over 100,000 votes between ballot papers. Like the SNP picture, we shouldn't oversimplify what was going on under Labour's grand totals. It almost certainly wasn't a tit for tat drop. Voters will have moved in, and out of, Labour's constituency and regional columns. But this was a discernibly squishier performance than the Nats in a closely contested campaign. In the event, Labour holds in constituencies in their traditional heartlands staved off some of the harsher consequences of this "voter promiscuity" in 2011. But if all does not go well for the party in its constituency battles in Glasgow and elsewhere - a gap of anything like 100,000 people is seriously going to hurt. And this, before we get into questions of differential turnout.

Part of me wonders if the electoral map in 2016 doesn't encourage an awkward dynamic for Kezia Dugdale, likely to encourage opponents of the SNP to lend her their constituency ballots, while distributing their regional votes elsewhere.  

Imagine you are a Labour voter of what we'll call the Alex Massie tradition. You voted No in 2014. You don't much care for the Nats. You live in a constituency where the Tories or the Lib Dems cannot prosper, where they're not even in the running. What do you do? Option One: damn the arithmetic and vote for what you believe in. If the local Tory or Liberal Democrat gains only a couple of thousand votes? Well, you salute their efforts. Alternatively, you might consider Option Two: use your constituency vote tactically vote for the Labour candidate most likely to frustrate the SNP. In Leith, say, you might support Lesley Hinds. In Glasgow, you might take a punt on Johann Lamont against Humza Yousaf. 

If Option Two seems attractive to you, however, there is a snowball's chance in hell that you're going to stick with the Labour party in the regions. You might also have a soft spot for one of the smaller parties who are only really in contention in the regional list. Perhaps you favour Brexit, and want to see a David Coburn, rolling around Holyrood, blaggarding the European Union. Perhaps Patrick Harvie seems like a sound character, and you want a decent Green delegation in Holyrood, advocating environmental concerns.  In local elections in areas in which they do well, the Greens are pretty transfer happy from a curious range of sources, including Scottish Tories. Perhaps you'd like RISE, modestly, to rise.

Given the parts of the country where Labour remains strongest against the SNP, I'd suggest the calculating anti-Nat and the floating, unpartisan, split-ticket voter is far more likely to cast a - perhaps doomed - constituency ballot for them rather than the vital, life-giving regional support Dugdale needs to survive. In fairness, recent polls suggest Labour's performance across the two ballots is pretty solid, at a (dismal) 18% to 19%.  A squishy list vote may be the least of her concerns. Time will tell.