ITT: people who don’t understand that Medicaid is not Medicare, and that means-testing means a service isn’t “for all.”

Editing to add: Medicaid is funded mostly by the federal government, 69% vs 31% funding from the state. So even if it wasn’t means-tested (one has to have an income below a certain amount, or be disabled to a certain degree before qualifying) it would not meet OP’s definition, a single payer health insurance system funded by the state.

To answer OP’s question, a state funded single payer health insurance program would likely run afoul of the Commerce Clause of the constitution which states the federal government has jurisdiction over interstate commerce. UHC, Aetna, and other nation-wide insurance companies would absolutely sue over the state programs interfering with their right to conduct interstate commerce, and they would almost certainly win, even without a hard right SCOTUS like the current one.

Because for all the big talk and anti-rich/anti-corporate talk that many Dem politicians preach--they aren't really willing to do anything other than talk about it in order to get votes.

Republicans aren't out to help you. Democrats aren't either. And most of Lemmy is too busy playing PokemonGO, to actually do anything close to a revolution that would change anything. They'll talk about it, upvote it, but they won't actually do it. lol