On Sunday night, three Senate Republicans — Lamar Alexander, John Barrasso and Orrin Hatch — published a Washington Post op-ed promising that if the Supreme Court rules against Obamacare and rips subsidies out of federal exchanges, "Republicans have a plan to protect Americans harmed by the administration’s actions."

The problem is they don't have a plan. And Republicans spent the last week showing that even if they did have a plan, there's no way the House would pass it.

Let's start with GOP plan, such as it exists, or doesn't. "First and most important," the three senators write, "we would provide financial assistance to help Americans keep the coverage they picked for a transitional period."

How long is this transitional period? What happens when it runs out? They don't say.

Next, they promise to "give states the freedom and flexibility to create better, more competitive health insurance markets offering more options and different choices."

There's nothing wrong with this idea, but to a great extent, it already exists. Section 1332 of the Affordable Care Act permits states to design replacements for Obamacare so long as their new system covers as many people with insurance of similar quality. So far, no state has tried. (To be clear, the waivers begin in 2017, but as of yet, no state seems to be seriously preparing to use them. Though that may change!)

Republicans could supercharge these waivers, perhaps by offering legislation to let states meet the requirements despite covering fewer people, or offering less comprehensive insurance. But the senators don't provide any detail on this front.

And...that's it. Seriously. There are no more ideas to be found; no more detail to be had. This isn't a plan. It's the barest possible sketch of some nascent ideas that could, one day, be used as the basis for a plan.

The bigger problem: Republicans can't pass a plan

But even if the op-ed included more details, the bigger problem is there is absolutely no way House Republicans will permit Senate Republicans to save Obamacare. House Republicans won't even let Senate Republicans fund the Department of Homeland Security. The Department of Homeland Security!

The idea that the Supreme Court will gut Obamacare and House Republicans will instantly vote to keep the subsidies flowing so long as states get a bit more flexibility to design their alternatives defies belief.

It would be one thing, of course, if this op-ed had some prominent House Republicans signed on as co-authors. But there's not a House Republican's name to be found on the document. Instead, there's this: "We have had many discussions with our Senate and House Republican colleagues on this issue, and there is a great deal of consensus on how to proceed. Many of our colleagues have good ideas, and we look forward to working together."

"We look forward to working together." "There is a great deal of consensus." That is not the language of people who have agreed on a plan.

If the Supreme Court rules against Obamacare, Congress will do nothing

There's a game behind the game here: Republicans want to persuade five members of the Supreme Court that it's safe to rule against Obamacare — they want the Justices to feel secure that Republicans will fix the mess, rather than letting it become a sucking wound that turns the country against both the GOP and the Roberts Court.

But they can't actually promise that. They don't have a plan to fix Obamacare, and they don't have a plan to pass the plan they don't have to fix Obamacare.

Of late, it's become fashionable in Washington to predict that Republicans won't be able to bear the consequences of a ruling for the plaintiffs in King v. Burwell. I think that's ridiculous. If the Court rules against the Obama administration, the outcome is perfectly predictable: nothing will happen. Some Republicans will come up with some plan to gut Obamacare that the Obama administration could never accept. The Obama administration will ask Republicans to simply fix the law, which they'll never do. The two sides will blame each other just as always happens, and their attached partisans will think their side has the better of the argument, just as always happens. We have seen this movie before.

The result will be a replay of the Medicaid mess that emerged from the Supreme Court's first Obamacare ruling. Just as in that case, Republican-led states will be able to receive the federal money by simply choosing to participate in the program (which, in this instance, means building an exchange). The economic logic of participating will be overwhelming: while the Feds kick in 90 percent of the cost of the Medicaid expansion, they pay 100 percent of the cost of the tax subsidies. But the partisan pressure to resist will be strong.

In the end, some red states will end up building their own exchanges, just as some red states have accepted the Medicaid expansion. Some red states will hold out, at least for a few more years. America will develop a two-tier health-care system, in which blue states that participate in Obamacare are subsidized by red states that don't.