Perhaps there is something mildly tawdry about discussing an issue such as gay marriage in terms of its impact on perceptions of the Tory party or the extent to which it helps the Tory evolutionary project. It is, after all, a rather larger, better issue than that. A Conservative who only supported equal marriage for these tactical reasons would be a poor and shilpit thing indeed.
Yesterday the Scottish parliament, catching up with Westminster, debated gay marriage. The best speech was that given by Ruth Davidson, leader of the Scottish Tories. It shows her - and her party - at their best and is well worth six minutes of your time.