This is a serious issue for every transperson in the United States, not just California, because California sets the precedent in many social issues. When the anti-SSM amendment was passed in California, several other states put their initiatives on hold or slowed them down until the recent US Supreme Court victories. What happens in California very often does not stay in California.
Take this threat seriously. The opposition has spread fear and lies and disgusting demonizations of transgender people, not helped by the recent Pacific Justice Institute’s fake and libelous “news” about a transgender student harassing girls in the bathrooms in Colorado. Remember how everyone thought that California would laugh at an anti-SSM amendment – only to discover that a large number of minority groups came out of the closet as “sudden conservatives” to vote against civil rights?
A loss to hate in California will hurt us all in the long run. I’m not certain what we outside of California can do to help, other than keep spreading the word and the positive message of civil rights.