  We are increasingly subjected to the power of AI authorities. As AI decisions
become inescapable, entering domains such as healthcare, education, and law, we
must confront a vital question: how can we ensure AI systems have the
legitimacy necessary for effective governance? This essay argues that to secure
AI legitimacy, we need methods that engage the public in designing and
constraining AI systems, ensuring these technologies reflect the community's
shared values. Constitutional AI, proposed by Anthropic, represents a step
towards this goal, offering a model for democratic control of AI. However,
while Constitutional AI's commitment to hardcoding explicit principles into AI
models enhances transparency and accountability, it falls short in two crucial
aspects: addressing the opacity of individual AI decisions and fostering
genuine democratic legitimacy. To overcome these limitations, this essay
proposes "Public Constitutional AI." This approach envisions a participatory
process where diverse stakeholders, including ordinary citizens, deliberate on
the principles guiding AI development. The resulting "AI Constitution" would
carry the legitimacy of popular authorship, grounding AI governance in the
public will. Furthermore, the essay proposes "AI Courts" to develop "AI case
law," providing concrete examples for operationalizing constitutional
principles in AI training. This evolving combination of constitutional
principles and case law aims to make AI governance more responsive to public
values. By grounding AI governance in deliberative democratic processes, Public
Constitutional AI offers a path to imbue automated authorities with genuine
democratic legitimacy, addressing the unique challenges posed by increasingly
powerful AI systems while ensuring their alignment with the public interest.
