THE row between Labour and the SNP over what to do about the Conservatives' cuts to tax credits certainly stirred up social media. It was like reading Irvine Welsh and the Dialogues of Plato at the same time.

One timeline would be full of the usual, boisterously tribal argy-bargy, another with arcane debate about Scotland Bill clauses, HMRC processes and the semantics of "reversing" cuts, "restoring" payments or "topping up" tax credits. Neither strand added much to the sum of human knowledge.

The picture is actually pretty clear.

Labour said it would compensate in full 250,000 Scots households who stand to lose £1300 on average as a result of cuts to tax credits.

The SNP tied itself in knots over whether this would be possible under the new welfare powers being devolved to Holyrood. When it untied itself, it adopted a perfectly reasonable position. If you missed it, don't worry. This is what next year's Holyrood election will be about.

Unusually, the SNP blundered badly by entering Wednesday's Holyrood debate on the issue claiming a future Scottish Government would not have the powers to act.

David Mundell, the Secretary of State for Scotland, had laid out the position clearly two days earlier and, though it took until Wednesday to see his Scotland Bill amendments in black and white, there could be no real doubt about their impact.

By the end of the debate (by the end of his opening speech, in fact) Social Justice Secretary Alex Neil was forced to acknowledge as much. An unwise delaying tactic had failed.

It put the Nationalists on the back foot, appearing unsure about how to respond to Labour's initiative and unwilling to address it.

But this 24-hour red herring caused only a temporary red face.

By Thursday, when Nicola Sturgeon knew she would be challenged at First Minister's Questions, the Nationalists had a clear riposte. They would wait for George Osborne's spending review later this month, which will reveal the Scottish Government's budget, and they would wait for the final detail of the tax credit cuts, which the Chancellor has promised to revisit following the policy's defeat in the Lords.

It is the sort of sensible, managerial position you would expect from a centrist, instinctively cautious government.

She promised nothing, but Ms Sturgeon's language provided clues as to her approach.

She spoke of "credible, deliverable and affordable plans to protect low-income households". That suggests the SNP will take wage rises into account and then do what they can to make up the difference between what people lose in tax credits and anything they might gain from the living wage.

That's very different from Labour's pledge to "restore in full" the tax credits and on this issue, as things stand, there is little doubt whose side the 250,000 households facing a financial hit should be on.

But of course, elections are about more than just one section of voters. After stumbling, the SNP has now planted its feet firmly in the centre ground – where elections tend to be won and lost.

It's where Labour might have been not so long ago but now the party's most pressing concern is to start winning back some of the traditional left-wing voters who have deserted it for the Nationalists.

Kezia Dugdale's tax credits policy puts Labour clearly to the left of the SNP and also highlights the gulf between the Nationalists' radical rhetoric and the reality of their policy-making.

The other question is one of affordability.

Labour's plan to implement neither the Conservatives' proposed income tax cuts for higher earners nor the SNP's planned air passenger duty cut would not actually generate any revenue to pay for tax credit top-ups.

However, it would give a Scottish Labour administration a bigger pot of cash, making top-ups easier to afford.

Again, the election looms into view. By not reducing the threshold for higher rate income tax, as the Conservatives propose, Scots earning £50,000 will be something like £1,300 worse off than those on a similar salary south of the Border.

Will the SNP be forced to follow suit? If it does, we can expect the Tories to hammer both parties as being pro-high tax and anti-aspiration come the election.

A new kind of Holyrood politics is finally emerging, where the parties face far more complex choices. For the voters, that means we'll get to choose between very different parties next May.