> Federal preemption is well established

In what? Source?

CFTC seems to be preëmpting state gambling laws under commodities regulation (specifically, as "excluded commodities"). That sounds, to me, like a major question. The sort Chevron deferred to regulators. The kind our current SCOTUS says should be decided by the Congress. To my knowledge, the Congress has said nothing about prediction markets. Which means it's in the domain of states.

Otherwise, fuck it, let's launch a prediction-market based national health insurance market. I'll sell you a contract that pays my medical bills if I have a health event.