I like what you said EvilTwins.
My DD has not been invited to some parties over the years. I have not taken offence and neither has she.
For her parties, I have always told her to choose who she wants (one year she had the most dreadfully rude boy there but I just grit my teeth because she obviously saw him as a friend - incidentally he never targeted her, just others). I did worry how this would affect those he did target who were at party but just kept an eye out and in end, apart from some odd words exchanged, nothing bad happened and party was a success. This year we had a maximum number - DD got quite stressed so in end she chose the last couple out of names in hat because she thought it was the fairest way as she liked everyone the same! She chose not to invite two people who had been extremely unpleasant to her during the year (and before you say she must have done something to antagonise them, no she did not as both were equally unpleasant to a few others). I didn't care who my DD invited as long as she was happy. It would have been hard to understand if she had invite the two unpleasant ones but hey it is what we do for our kids.
This thread I think would assume that I am being petty here? I actually gave her the choice of inviting these two, indeed to be the better person, but she chose not to and no way was I going to force her, just for everybody else to have an opinion on. I did not want her to be unhappy at her own birthday party.
Regarding SN children, I think it is unfair to exclude on basis you think they won't cope. Surely if your child wants to invite a SN classmate then it is up to them? As the parent you then speak to the parent of SN to see if there is anything they require, allergic to etc? That is just common courtesy? On the other hand, if your child does not invite their SN classmate because they don't really socialise with them, then I think that is understandable.
I agree, it is a very very difficult issue to invite whole class bar 1 child (whether that child is bully or SN or whatever) BUT I am still on the side of the children and who they choose to have at their own party. Sorry if this makes me a bad person/mother. It is just my opinion, it is neither right nor wrong x