system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is preventing blue states from enacting single-payer/universal healthcare?
gpt
Most US states have constitutions that would permit this, or at least have a mechanism for amending their state constitution to permit this.

What's preventing it is lack of desire to raise taxes or regulations in just one state, because that might drive businesses or wealthy individuals to move to an adjacent state. By contrast, if *all* states do something, that risk is lower.