Could a weaker central government work in the US today?

[Ancestral Republican]

It basically is already pretty weak. That's by design.

A central plank of far-right organizations like the Federalist Society, Heritage Foundation, etc is to make the government nonfunctional. The point of something like overturning Chevron(which grants federal agencies some deference in their operation and decisionmaking powers) is to force all new policies to go through Congress. Congress is, thanks to the slavery-based filibuster, basically useless. If agencies are told they can't act without Congressional approval, they can't act. The corps love that for two reasons - one, they are mostly regulated by agencies, and will no longer have to worry about that pesky EPA or NLRB; two, people recognize that government isn't functional, don't understand why, and attribute it to some ethereal idea of "the gubmint don't want to work." Wouldn't it be better if our mail was delivered by FedEx instead of the USPS? Oh, btw, stamps now cost $6.74.

To the point in the original post, a state can't really implement universal healthcare on its own. American healthcare prices are bloated beyond belief by design, and budgetary estimates for states that have looked into doing this are based on those fake prices, and arriving at truly outrageous numbers not at all reflective of the true expense. It won't work unless you control the whole system, and then you're actually saving money once you stop paying the fake prices and stop having to funnel your money through useless third party insurance middlemen.