This is the second part of the exploration of 'thinking clubs'. This is someone who does all the organising work - usually an unthanked task. This organiser could be called a 'convenor' if you like grander titles. That person can remain the organiser for ever. Too often such a person is soon democratically voted out of office by power plays in a committee.
Many people are much better at playing politics that at taking initiatives.
They wait for someone to take the initiative then move in as parasites - and eventually kill the organism. So no democratic committees unless you want them. Those who do not like the way things are run can vote with their feet. Join another thinking club or set up one of your own. I would strongly suggest that the organiser has a partner or deputy who can take over if the organiser has to be absent or is ill.