So the public option isn’t quite dead yet. Democrats – Harry Reid, no less – showed some spine. Progressive advocacy groups are ecstatic. Conservatives are aghast.

But before anyone on the left (or right) gets too excited, it’s worth taking a clear-eyed look at what the "opt-out" actually entails. As the ever-shrewd Ezra Klein has observed, "It is a compromise, and a conservative one at that."

The option of a government-run plan will apparently only be offered to people who don’t rely on employer-based insurance, and only in some states. Is this an improvement over the status quo? Certainly. Is it a formula for universal coverage? At least in the short-term, it’s more likely to bring about a patchwork system in which less affluent people in more conservative states end up being denied choices that individuals who happen to live in places like Boston and New York enjoy.

This is exactly the way the system works for something else: abortion. Since passage of the 1977 Hyde Amendment, which forbids the use of federal funds for most pregnancy terminations, the decision of whether or not to pay for abortions for poorer women has fallen to the states. As any reproductive rights advocate will tell you, the result is far from ideal. Massachusetts, New York, California and fourteen other states subsidize abortion procedures for women who can’t afford to pay for them. Mississippi, Kentucky, Oklahoma and thirty other states do not.

"Choice" in America thus varies dramatically depending on where a woman lives and how wealthy she happens to be. The system is fair only in that it accurately reflects what’s missing: a broad social consensus that reproductive rights should be available to all.

The "opt-out" is premised on a similar kind of tacit admission: since no consensus can be reached on what is desirable, states will be allowed to experiment and design their own systems. Beyond the uniquely polarizing passions that swirl around abortion, the one major difference is that, whereas the Hyde Amendment forces states to provide funding for a medical procedure that the federal government as a rule does not underwrite, under the "opt-out" states will have to proactively deny a more affordable health insurance option to their citizens. It may well be that even many conservative governors will lack the stomach to do this. But, if the ‘opt-out’ ends up becoming law, nothing will be in place to stop them.