I have a much more positive take on this. My mom started a group back when I was a kid, and I'm now a member of a 3yo local support group. Both were REALLY helpful. Teachers don't really even know who is a member and who isn't. All parents are welcome to attend--we don't check IQ scores at the door--so there's no bad vibe about it in the schools. And ou group has helped other groups in surrounding areas get started. It's been a fantastic experience!
We do accept members from the geographical area, not just from the public school system, so that might help. It's not a slam on the public schools or anything, and we work very hard not to just go off on them ever. Calm and polite are the watchwords, just as they are in any form of advocacy. The GT coordinators for the schools often attend meetings and they love the forum it provides them. We give an award for "best teacher or adminstrator" who works hardest/best for GT kids. Lots of positive reinforcement! And we have really raised awareness of GT issues in the school system. In the last election, GT issues were discussed by school board candidates. That would NEVER have happened before!
I'd recommend finding a core group you can count on to always attend. Even if they don't do a lot of work for you, having people show up at the meetings is key. There's nothing worse than trying out a new group, only to find that it's you and the organizer and no one else.
Publicity is vital. Getting notes into kids' bags at school is probably your best bet. If you want to include private schools and homeschoolers, too, get info to those groups as well. Post something at the library. Get meeting info into your local paper.
The NAGC (or your state branch of it) can probably offer you some help, too.
Consider what sorts of programs you want to run. Successes for our group have been hosting testing experts to talk about the process and sample results (This was why I realized that DS7 was more than just MG...), "Games Night" for families, summer camp opportunities, math for GT kids, local educational options (private schools, homeschooling, etc.), advocacy 101, perfectionism and underachievement (led by a SENG expert), 2E issues, etc.
We also have a couple people who advocate at the state and national level. That wouldn't be required, but if you have someone who is fired up and wants to do it, it can be a good thing.
A lending library might be nice if you have books about GT kids that you can share.
Some groups even host enrichment classes for GT kids. That might be a good long-term goal if there's nothing like that offered in your area. (Or not...Just tossing it out there!)
I am not the person who started our local group, so I'm not an expert. But I'd be happy to talk more if you think I can help more.
I do think a good support group can make a HUGE difference in a community. Naturally, just having a place to talk to other parents of GT kids helps immensely. And being able to ask questions about the local landscape for GT kids is really useful.
FWIW...
