THERE are mutterings by some SNP figures, close to the party’s hierarchy, that the centre ground needs to be maintained and reclaimed. The Yes movement seems to be polarising. The divisions are most stark when it comes to both the best route to achieve independence, and around equality issues like trans rights.

In the crudest of terms the divisions break down something like this: if you’re on the Salmond populist wing of the party then you probably favour moving as quickly as possible towards independence via either a so-called ‘consultative’ or wildcat referendum, without Westminster consent. You might even support a unilateral declaration of independence. Some, but not all in this camp, are also more likely to be uncomfortable with, or angry about, plans to make it easier for people to change their legally recognised sex.

If you’re on the Sturgeon social democratic wing then you want any second referendum to be by the book and 100% legal, even though that’s a long, uphill struggle. You’re also more likely to be relaxed about, or in favour of, legal changes around gender which favour trans people.

Rightly or wrongly, the battle between Joanna Cherry and Angus Robertson for the SNP nomination in Edinburgh Central is seen to represent this divide: with Cherry perceived as in the Salmond camp, and Robertson in the Sturgeon camp.

The opinion of individual party members is, of course, much more complicated and nuanced than this relatively blunt summary - plenty, for example, might support a wildcat referendum and also favour trans rights. However, there’s also truth in the public perception of SNP tensions.

Manoeuvrings against Nicola Sturgeon seem to confirm the perception. The party is at odds over the leadership. Some would oust Sturgeon; others are loyal.

The party even turns on itself over issues which don’t need to cause division - like the recent story about a drag queen visiting a Scottish primary school. Some parents voiced concern. The SNP’s Mhairi Black accused critics of homophobia. Party members appeared split, with some outraged at Black and others supportive.

To make matters worse, the SNP’s new PR chief, Murray Foote ex-Daily Record editor, clod-hopped into the story. After he initially compared drag to pantomime on Twitter, Foote was then hit with a wave of criticism - including from many independence supporters - and had to issue a clarification saying that his comments hadn’t reflected “legitimate parental concerns”.

What makes the story remarkable - aside from the fact that people still haven’t learned to stop self-harming via Twitter - is that the SNP never used to wash such dirty laundry in public. The more that divisions open up, though, the less capable the SNP seems of retaining its once legendary discipline.

Why is this happening? Perhaps we need to listen to those quiet voices talking of the need to reclaim and maintain the centre ground.

The divisions in the party have deep roots which go back to the days before the first referendum. When the idea of independence moved from the fringes of political life to the mainstream in the years running up to 2014, it was a concept mostly in the hands of elites.

Independence was moulded by political thinkers, academics, writers, and artists. Independence prior to 2014 was something of a Salon issue. There was an avant-garde air to it. It felt radical, metropolitan. It had bohemian, youthful appeal. Alasdair Gray was the guiding spirit of independence.

Think of the organisations which sprung up during the referendum - Women for Independence brought a vibrant, necessary feminist voice to the conversation; National Collective spoke for artists and writers who backed Yes; the Yes campaign itself was staffed with bright, young intellectuals. Think-tanks like Common Weal were established, creating a leftwing agenda for an independent Scotland.

It was a progressive, modern, vibrant, social democratic vision of independence which was offered to the nation. This was the Yes centre ground.

After 2014, with some notable exceptions, the Yes movement effectively mothballed itself. Two things happened: independence was left to the SNP to shape alone, and Yes activism migrated online.

Following the immutable laws of what happens to an intelligent debate once it gets stuck in social media land, the Yes campaign quickly developed an ugly, nasty side due to the behaviour and opinions of its leading online personalities.

Of course, unionist ultras online had behaved despicably to Yes voters throughout the independence campaign, but quickly the voices of so-called ‘cybernats’ seemed to rise louder than some of those in the SNP.

Then the big change happened - the Yes movement started to morph into a street movement. Soon, there were marches all over Scotland with plenty of flags and banners, but little real discussion or debate. The SNP hierarchy kept itself conspicuously absent from most of these events.

So the grassroots of the Yes movement - the heart, the soul, the engine - moved from being dominated by Scotland’s elites in the world of politics, the arts and academia to being primarily influenced by an angry online contingent. The online world then formed a street mass movement. That’s one hell of a change in just a few years.

When SNP figures mutter about a need to reclaim the centre ground, what they mean is a need for the party hierarchy to take back control from a grassroots that now frightens it a little. This was inevitable. SNP leaders whipped up their base with continual false promises that ‘indy is coming’ - eventually that base would grow discontent.

The base no longer seems a fit with its centrist, social democratic leadership. Common cause seems to be easier found with the more populist Salmond wing of the party.

That bodes ill for the SNP’s hierarchy. It also bodes ill for the party. The SNP has won so many elections as it presented itself as a centrist party with a leftish bent. If the centre doesn’t hold in the SNP, what will that mean for its until now unbeatable electoral fortunes at Holyrood in 2021, and more importantly, what will that mean for independence?

Split parties repel voters, and when it comes to an issue of such huge social change as separation from the rest of the UK, it's the centre ground of voters who must be convinced, if independence is ever to be won.

Neil Mackay is Scotland’s Columnist of the Year