Who organized the illegal immigration marches?
There's a long article here listing some of the groups involved: unions, Catholic clergy, far-left groups, and even teachers unions.
He notes also that the Georgia immigration march was organized by former Mexican General Consul Teodoro Maus. However, he fails to mention that it was apparently your blogger who brought that to wider attention; I just linked to Allan Wall's earlier article about that consul.
In any case, if you want to know who else is on the other side it's got lots of names.