This tower will fall
I used to play Jenga as a child, and I have always remembered how often the most stable-looking tower would crumble, when a single, seemingly unimportant block was removed. That tower reminds me of the current SNP, as Nicola Sturgeon and her cronies pull the blocks out from under themselves.
In a recent contribution to the Spectator it was noted that, despite the SNP and Nicola Sturgeon's woeful handling of a myriad of domestic issues, she and her party remain popular amongst Scottish voters, seemingly defying electoral and political gravity.