but maybe militant is a good comparison?
And clearly the Scottish Nationalists are capable of mobilising a large section of public opinion around their programme, which Militant never were (and were never interested in doing).
An interesting discussion.
Just briefly as I don't want to derail the thread. Yorky is right in his point above, however Liverpool Militant were capable of mobilising support locally. My recollection is the City wasn't great under the Liberals (they were regarded as Tory-light) and the conventional Labour party couldn't get a foothold, so their arrival at that time in the Thatcher era was welcome. To us here anyway.
Of course they were going to have to be dismantled because their style of governance was a very selfish one, albeit many in the city benefited.
A further recollection was that they were very much a 'jobs for the boys' organisation. Many people gaining employment in the City Council at that time came from their ranks.
During another period, there was a point when you couldn't even be shortlisted for a job at the council if you were not unemployed.