In supporters trusts as with unions there will be those individuals whose motives are not purely selfless, be it the influence they can exert to achieve particular outcomes or purely to share their own opinions. Unions are a necessary evil as without them the gap between rich and poor would be far wider and there never would have been the collective funds to underwrite a political party. It is this which I personally grudge with union membership, a political levy now would just fund more of the same policies which has gotten this country to where it is now. Not good.
Please note this is not a slight on the ICT Supporters Trust but a general comment.