I'll obviously have more to say about the proposal, whatever it contains, once it's official. In the meantime, though, I hope that anybody writing on these proposals mentions, prominently, that rolling back the Affordable Care Act's Medicaid expansion would entail taking health insurance away from about 15 million people. That's the official, Congressional Budget Office projection of how many people will get coverage under Medicaid once the Act is fully in place.

As for turning Medicaid into a block grant, here's a quick refresher on what that involves. Right now, Medicaid is an entitlement program. That means the federal government, in partnership with the states, must enroll everybody who meets the program's guidelines. In other words, if millions of additional people become eligible because, say, they lost their job-based insurance in the recession, than the feds and the states have to provide them with coverage and find some way to pay for it. And it can't be spotty coverage, either. By law, Medicaid coverage must be comprehensive.

At least, that's the way it works now. If the law changes and Medicaid becomes a block grant, then every year the federal government would simply give the states a lump sum, set by a fixed formula, and let the states make the most of it. Conservatives claim block grants would give states the flexibility they need to make their programs more efficient. But, as Harold Pollack has noted in these pages, states already have some flexibility. And because demand for Medicaid tends to peak during economic downturns, when state tax revenues fall, the likely impact of a block grant scheme would be to make Medicaid even less affordable at the time it is most necessary.

That's not to say plenty of governors wouldn't take advantage of block grant status to change their Medicaid programs in ways they cannot now. They surely would--by capping enrollment, thinning benefits, increasing co-payments, and so on.