Does Sturgeon/Salmond battle mirror deepening cracks in SNP?

The Scottish Parliament is about to vote on a motion of no confidence in the SNP’s Deputy First Minister John Swinney.  He’s expected to see off the challenge, but it’s a reminder of the seismic shock to Scotland’s politics caused by the Alex Salmond affair.

But does that very public row at the top of the SNP conceal deeper divisions over party strategy and Nicola Sturgeon’s leadership?