Hes right to a certain extent.
When there is a low turnout, all the polls go completely out the window.
However with a high turnout, if 100% of the people they expect to vote actually do so, and the pollsters have got their methodology correct, then the polls will be pretty accurate (by and large). Determining how the folk in castlemilk and easterhouse will vote, however, and how many of them will vote, puts a spanner in the works.
The old folks will always get their vote out, that much you can guarantee. However the young, those that dont generally vote, and the poor hold the key to this referendum.
If we get high percentages in the schemes, we'll win. Thats why these turnout numbers are so important.