With John McCain due to return after his surgery and serious cancer diagnosis, GOP Senators are poised to attempt a vote (again) on health care. However, this time they will be voting on a procedural vote to start discussion on the House-passed American Health Care Act (AHCA)–remember that one? However, if the motion to proceed is successful, what follows is an open question. In other words, this is not an attempt to pass the House version. Instead, it is a vehicle to enable the Senate to come up with something of their own, allowing anyone who wishes to offer an amendment during the debate.

What is not clear is how well-planned the amendment process will be. Apparently, there is a mid-day meeting of the minds today to discuss this. However, we could start to imagine the range of amendments that could be offered:

  • Some version of the Senate Bill, the Better Care Reconciliation Act (BCRA), could be offered, with or without the Cruz amendment. Importantly, last week the Senate Parliamentarian ruled that some of the provisions of the BCRA–namely the ones that essentially defund Planned Parenthood–violate the rules of reconciliation, and thus would need 60 votes to proceed.
  • We have also seen the re-emergence of a proposal to repeal Obamacare without a replacement, going back to where this debate originated. The most formalized version of that is the Obamacare Repeal and Reconciliation Act (ORRA).
  • The Cassidy-Collins proposal, the Patient Freedom Act, offers three paths for states in a post-Obamacare world: keep Obamacare, adopt a different form of insurance expansion, or eliminate insurance expansion all together. While this may sound like a reasonable compromise to some, it is worth noting that even the “keep Obamacare” option would still result in less federal funding for states.
  • Then of course you could envision some form of single payer waiting in the wings. Surely, we know there would be no majority vote for that amendment right now, but there does seem to be at least some growing support among Democrats. More on that to come.

While we will have to wait for the vote tallies to know for sure, here are a few things to watch:

  • Republicans need 50 yeas to move forward with the procedural vote and to pass a bill. That means no more than two defections (with a Mike Pence tiebreaker). Last week, three female Republican Senators (Susan Collins of Maine, Shelley Moore Capito of West Virginia, and Lisa Murkowski of Alaska) prevented a procedural vote from moving forward for a repeal and delay measure. Reportedly, Susan Collins has said she will vote no on any of these procedural measures, unless a brand new bill emerges.
  • Previously, some Senators wanted to know what the bill would be before voting on whether to allow discussion. Senator Rand Paul (R-KY) is among the most ardent opponents of moving forward on anything that is not close to a full repeal. It is unclear if this position will block the procedural vote.
  • If the vote to proceed moves forward, there is no guarantee that a final bill will pass. Instead, what would follow is a “vote-a-rama” in which any number of amendments could be offered, needing a majority vote for each amendment to be included.

Given the persistent disagreements, it is hard to imagine that a magical compromise will succeed in this environment. Still, every time we think the Obamacare repeal and replace debate is over for good, it seems to rise again.

For tracking developments and votes today, follow the NYTimes’ live updates and vote counts, and if you are really interested in watching this all unfold, tune in to C-SPAN’s live feed.