Why is the California nurse’s association a leftist organization?

[uniteddemclub, BSN, RN]

They supported progressive left Chesa Boudin (former DA of SF who has been recalled) and I saw comments on Twitter claiming Cal Nurses only endorsed him because the drug overdoses keep them working, and every crime victim and drug user will have a job. Chesa was blamed for rising crime and drug ODs by critics on the right. I’ve also seen claims that while the nurses association supported Chesa Boudin, nurses independently do not. I’m so confused because I’m a nurse who supports Chesa. Not even just Chesa, but every political endorsement they make is liberal or even progressive left. Why is it that way and do they represent the political views of California nurses in general?