> Georgia spent ~$47.5B, but only collected $21.5B in taxes, with much of the rest ($14B) coming from the federal government or bonds. So...federal spending has a lot of leverage.

The Federal government has no right to rescind bonds to States, any more than they have the right to rescind bonds to foreign entities — the stability of US Treasury Bonds is predicated on the Federal government's reliability as a creditor. States also have the ability to issue bonds to pay for programs. Georgia enjoys a AAA rating, one of the highest credit ratings in the Union.

Also, we're just talking about Georgia here, the Federal "aid" as a %age of revenue varies from State to State.

Also the structural gridlock built into the Federal government swings both ways, and you need a filibuster-proof majority in the Senate too be able to do what you're proposing, for instance, decide to cut off Medicaid funding writ large, just to spite certain states. The minority rights baked into the Senate make it incredibly difficult for the Federal government to come down hard on any individual state, in the same way that it makes it difficult for the Federal government to pass laws even if we were able to eke out a simple majority support for that issue.

> "Get with the program, or we're moving the CDC/National Primate Center/etc to Rayleigh-Durham" would certainly get some state politicians moving. Not only is that a lot of money, but those are also good jobs and prestigious institutions. I agree that totally cutting off funding from an agency would be unlikely, but it's not totally unprecedented (55 mph speedlimit and raising the drinking age). And of course, there's the middle ground of changing priorities with a wink and a nudge.

First of all, as mentioned above the Federal government doesn't really have unchecked power to jsut decide to up-and-move the CDC. Second of all, you've given me such an example to demonstrate leverage over Georgia, specifically, but the Federal government has no such leverage over nearly every other State. The States most likely to spearhead a State-level single payer program are probably New York, California, Washington, and Illinois. The Federal government doesn't really have much over them.

> As for language, no. A national language has been politically fractious in the US for decades. States do have them but they're all English, with some symbolic concessions to indigenous peoples' languages in a few states. Alaska's law, for instance, "does not require or place a duty or responsibility on the state or a municipal government to print a document or record or conduct a meeting, assembly, or other government activity in any language other than English." I doubt many people are renewing their drivers' licenses in Lakota or Hawaiian.... Compare this with Quebec, which requires that both official languages be used federally, and not only doesn't use one of them, but even has an office devoted to ensuring that the other isn't too prominent in provincial government or daily life.

I'm not sure what you are arguing here. First of all, we're not talking about a "national language", we're talking about the structural authority for States to define their own language...and there is literally nothing stopping the State of Texas from adopting Esperanto as its State language, if that was something that a majority of its citizens wanted. It just so happens that the majority of citizens everywhere are fine with English, and don't want to change that. Comparing this with Quebec doesn't really prove a point, because you're just giving me an example of a Province that has chosen to exercise this authority. I'm arguing that the US States have the same authority, but simply choose not to exercise it because there isn't the same political will. And further, while Canada recognizes official languages Federally, the United States does not — there is no official Federal language — and it's because this is one of the many matters left to the States.

> Likewise, states certainly can set their own taxes and level of social services, but Quebec itself has tax and social service treaties with other countries. Quebec also runs a parallel immigration system (selection/admission) that again, has treaties with other, mostly francophone, countries. No state in the US does anything like this; in fact, it's explicitly forbidden by the Contracts Clause (Article 1, Section 10).

Sure, again not really relevant to State single payer. And also practically, US States also enter into agreements with foreign entities, one example: California has a cap-and-trade agreement with Quebec. Over the last half-century, states and cities have concluded hundreds to the thousands of agreements with foreign national and subnational governments on a wide range of topics, including trade, tourism, transportation, family issues, sister-sister relations, security, traffic regulation, the environment, and agriculture[1]. Anyway, none of this is really relevant to the discussion at hand — that the level of sovereignty granted to the US states is more than sufficient to enact their own healthcare systems.

> In theory, the 10th Amendment suggests that they could be, but US v. Sprague and Darby Lumber Company basically gutted that idea: the reserved powers clause "added nothing", "states but a truism", etc.

Not really sure how US v Sprague is relevant here, it pertained to the language behind the Article V ratification process. US v Darby Lumber merely state that the Federal government has the right to regulate employment contracts. There's no dispute there, my argument is that States share sovereignty with the Federal government, and States also have the right to regulate employment contracts.

> In practice, the Commerce Clause and Supremacy Clause let the federal government do nearly anything.

Yes, again, the Federal government is empowered to do anything. But so are the States! The Federal government is empowered to start a Federal university system, or a Federal public school system, or a Federal fire safety system, but that doesn't mean that States are prevented from doing those things. The argument here is that, absent the political will to do something at the Federal government, States are empowered to step up. That's what the rigid system of checks and balances with minority rights at the Federal level encourages.

> I'm struggling to examples where US States are stronger than the federal government or their Canadian counterparts.

There are many. Sanctuary laws are one such example. The current Federal government is trying to come down hard against States that have sanctuary laws, but it hasn't really had much luck. Marijuana legalization is another example, it is still technically criminalized at the Federal level, despite being legal in a growing handful of States. The Federal government is empowered to set emissions standards, but States are also empowered to do this, and may even set standards stricter than those of the Federal government, which is exactly what we see happening in California. Net neutrality is perhaps the most recent example, where the courts ruled that the FCC does NOT have the authority to preempt state net neutrality laws[2].

Also, taking a huge step back, we are talking about States deciding to enact their own Single Payer healthcare systems — there is practically no reason for the Federal government to ever withhold funding for anything over that (indeed, Republicans encourage it), the gridlock baked into the Federal government makes that practically difficult, and the States that are most likely to enact such systems are those that have already historically exercised disobedience against the Federal government — to the extent that exercising a State's constitutionally held right to pass their own healthcare laws can even be construed as "disobedient".

[1] https://eelp.law.harvard.edu/2019/11/californias-cap-and-tra...

[2] https://arstechnica.com/tech-policy/2019/10/net-neutrality-s...