It's right here in the 2016 manifesto: We believe that the Scottish Parliament should have the right to hold another referendum if there is clear and sustained

It's right here in the 2016 manifesto: We believe that the Scottish Parliament should have the right to hold another referendum if there is clear and sustained evidence that independence has become the preferred option of a majority of the Scottish people – or if there is a significant and material change in the circumstances that prevailed in 2014, such as Scotland being taken out of the EU against our will. (https://d3n8a8pro7vhmx.cloudfront.net/thesnp/pages/5540/attachments/original/1485880018/SNP_Manifesto2016-web_(1).pdf?1485880018 https://d3n8a8pro7vhmx.cloudfront.net/thesnp/pages/5540/atta... - page 23) Quite aside from that, the obviously stated public policy of the SNP and the Greens is that Scottish independence is their preferred constitutional settlement. It's hard to imagine that one would vote SNP while being unaware that this was a possibility, and it's hard to imagine a more obvious and legitimate political move.