NEVER let a good crisis go to waste. The Brexit clusterbourach, as it is now officially known, has wiped every other issue off Scotland’s battered political consciousness. We’re all transfixed in horror at Westminster’s descent into constitutional madness. This presents an opportunity for the Scottish Finance Secretary, Derek Mackay, as he delivers his Draft Scottish Budget today. He could scrap council tax and slap a supertax on domestic pets and, right now, hardly anyone would notice. .