In May, House Republicans and President Trump celebrated dragging a health-care bill over the finish line by a few votes.

Senate Republicans promptly discarded the bill. It was too conservative, too politically messy and it wouldn't even pass Senate budget rules to avoid a Democratic filibuster. They'd have to write their own, pass it and figure out how to reconcile it with House Republicans later.

That plan failed.

So this Tuesday, which is probably Senate Republicans' last best chance to change Obamacare, they are right back where they started: No bill of their own, but a likely motion to proceed on the House-passed version of the bill. They have no plan for how to get it, or any other changes to health-care policy, passed. But they're hurtling toward a free-for-all vote Tuesday evening anyway.

This is remarkable. It's like making health-care policy by throwing spaghetti at the wall and seeing what sticks.

The plan is to hold a procedural vote to allow debate on the House bill, the one the Congressional Budget Office estimated could leave 23 million more people uninsured over the next decade than Obamacare. If that passes, Republican leaders will let senators throw a bunch of amendments at it and see what happens.

Possible amendments could include a full repeal of Obamacare, or a substitution of McConnell’s Obamacare overhaul, or whatever other changes to health care a Republican senator wants to make.

Put another way: Republicans are waving the white flag on health care. They have no idea how to get legislation passed in a party ideologically at-odds with itself.

“I think they just want to say they tried,” said Alice Rivlin, a health-care policy analyst with the Brookings Institution. “[Senate Majority Leader Mitch] McConnell (R-Ky.) may be genuinely unsure of the outcome and hoping for the best, where 'best' means anything that gets 50 votes.”

This is not normal policymaking. When Democrats passed Obamacare in 2010, they reasonably could have been accused of rushing through the final vote in the Senate. But this was after months of public hearings and debate. At the very least, the Democrats who voted “yes” and the Republicans who voted “no” knew what legislation they were voting on and the impact it would have on the health-insurance market and federal budget.

Contrast that with Republicans' process this year. Leaders literally wrote a bill in secret. That secret bill, and a second iteration, failed to get the support of 50 of 52 Republicans. And now, here's Sen. Ron Johnson (R-Wis.) talking to reporters Monday night, about 24 hours before an expected vote:

Even Sen. John McCain (R-Ariz.), who is expected to return to Washington after being diagnosed with brain cancer, has criticized his party's secretive process on getting to this moment.

Republican leaders point out that they modify House bills with amendments all the time, but that's not the usual practice for a piece of legislation that would affect one-sixth of the economy.

This isn't just a procedural mess for Republicans. It's a political one as well. They've spent seven years universally campaigning on the need to repeal and replace Obamacare. They finally have control of Washington.

The moment is upon them, and they don't have a bill to vote for. Nor any idea of whether it will pass. Nor any idea of whether it can even be voted on under budget rules called reconciliation that let Republicans avoid a Democratic filibuster. Basically, they have no plan.

In a couple of sentences Monday, Trump outlined the brutal reality for Republicans right now:

“Every Republican running for office promised immediate relief from this disastrous law. We as a party must fulfill the promise to voters of this country to repeal and replace, what they've been saying for the last seven years. But so far, Republicans haven't done their job in ending the Obamacare nightmare.”

Or, in one sentence: It doesn't look like Republicans are going to be able to repeal Obamacare anytime soon.