It's kind of sad that no one has answered you.
I have been, and continue to be a nurse "activist". There are others, such as Dr. Laura Gasparis Vonfrolio, buit they are far and few between.
Nursing organizations, with one exception, are grossly underfunded for political action. They simply don't have the membership for aggressive political action. The existing ANA leadership is satisfied to be invited to the table on health policy. Nursing activists would want to sit at the table, as equals. We have many issues in healthcare we could contribute to, but much of our "leadership" are affiliated with the American Hospital Association (the AONE) and the rest are primarily educators. Both groups have essentially distanced themselves from the core of nursing, direct patient care.
The one group that does seem to understand this is the NNU. I would suggest checking them out and joining if you feel so inclined. Go to the meetings in your area since you live in California. Find out how you can help. We can all support this group by simply joining, you don't have to be unionized. Empowering them empowers all of us.
That said, they don't champion Advanced Practice, so if you are interested in this effort you need to seek out the APN network in your state and contact them. There are always things to be done. Letter writing to your local paper, going on radio shows to talk to the public, and contacting and educating your local representatives and senators.
Now if you can just get over the inertia that most nurse seem to have, you will already be ahead of the curve!