I think we need to focus strongly on the persecution aspect, with a long list of documented examples of discrimination and mistreatment from various countries.

No, our identity is not the diagnosis.  Our people existed for thousands of years, all over the world, before anyone got the idea of labeling us as "disordered."  The existence of the diagnosis, with the ugly stereotyping that results from it, is the reason why we need protection as a minority group, but it is not who we are.

It's possible to describe the Autistic/Aspergian population without using the "official" diagnostic criteria.  Edan did it on Aspergia.  Baron-Cohen and Attwood have also written articles in which they set forth "alternative" descriptions of Aspies:

http://www.geocities.com/CapitolHill/713...bility.htm
http://www.thegraycenter.org/discovery_of.htm

I would also suggest describing some of our common traits in terms of family priorities, rather than individual behavior; this will give the impression of a multigenerational cultural difference.  For example, instead of saying that an autistic person is likely to prefer academic activities to social activities, we could say something like, "Our families historically have placed a strong emphasis on encouraging our children's academic interests."

I agree.  Gwynfryn mentioned that many traits of the autistic population are present in the general population to a lesser degree, but although that's technically true, it's not relevant to the civil rights issue.  That's like saying that everyone is a bit black because we all have pigment in our skin.