Citizens of California: How the golden state went from worst to first on immigrant rights

California has accomplished a remarkable shift in its historical development on immigrant rights, from pioneering and championing anti-immigrant legislation from the 1850s through the 1990s, to passing robust pro-immigrant rights policies in the last two decades. In this article, we unpack California’s policies and historical shift on immigrant rights, and develop a typology of regressive, restrictive, and progressive variants of state citizenship. We then advance a theory of how California’s progressive state citizenship crystallized in 2014 by cumulating and gaining sufficient strength in particular elements - of rights, benefits, and membership ties - to constitute a durable and meaningful form of state citizenship. Our work builds on, and speaks to, a fast-growing literature on immigration federalism and a robust literature on semi-citizenship and alternative types of citizenship. Situated in federalism, state citizenship operates in parallel to national citizenship, and in some important ways, exceeds the standards of national citizenship. While many states have passed various policies intended to help undocumented immigrants such as state driver licenses, in-state tuition, financial aid, health insurance for children, our concept and theory of state citizenship formation considers how California’s policies took more than a decade to develop and reach a tipping point, transforming in 2014 from integration policies to a more durable crystallized state citizenship.