This afternoon we may finally see the Senate take an actual step toward fulfilling Republicans' longtime promise to repeal Obamacare . Exactly what comes next, however, is unclear.

First things first. Before we know exactly what senators plan to pass, they have to begin the process. They haven't even had enough votes for that, up until now. But the chamber's second-ranking Republican is indicating they'll be able to clear that hurdle, at least:

One has the sense Sen. John McCain, newly diagnosed with brain cancer, wouldn't be returning to Washington unless his vote meant something (and if he planned to vote against the motion to proceed, he could have the same effect by staying home). Senate Republicans need only a simple majority in favor of this motion, because it pertains to budget reconciliation, and it appears one of the holdouts until now, Sen. Rand Paul, intends to vote for the motion:

Paul went on to say via Twitter that he would "vote for any all measures that are clean repeal," which he defined as "Repealing mandates & taxes, without new spending and bailouts. This is the path I've been urging, and what I discussed with (President Trump)."

But as you can see from his entire series of tweets, there are a number of bills and/or amendments that could come to the Senate floor if the motion to proceed passes. While Paul expresses confidence about the bills that can be defeated, it's far from clear what can actually succeed. The emerging consensus is on something being termed "skinny repeal": getting rid of the individual mandate, along with some combination of Obamacare's spending and taxes. Rather than get too hung up on which spending and which taxes, though, it's worth pointing out that the end-game here appears to be the same as it was when the House finally got around to passing a bill: simply passing a bill.

To use a football analogy, you might say the goal is to keep the chains moving rather than continuing to come up empty on big plays downfield and having to punt. A motion to proceed, combined with passage of some bill that gets the process back to the House, is like a legislative first down. It keeps the drive alive, and gets leadership a fresh set of downs -- more chances to make plays and eventually score.

The point of today's actions, then, is to lay the groundwork for a conference committee with the House in which a final compromise can be crafted that both sides can (and must) live with.

This is not the kind of process Republicans really ought to be proud of, nor one that allows them to continue using the line about Democrats shoving Obamacare down Americans' throats without fully knowing what was in it. It's always easier to point out procedural shortcomings when you're trying to block a bill, and the GOP will have to live with its long record of carping about that when Democrats were in charge. That said, it might allow the two chambers to come together on a bill that can pass muster with its various members and their often disparate interests -- e.g., red states that expanded Medicaid vs. those that didn't -- and finally keep the one campaign promise they must keep if they have any hope of continuing to lead Congress after 2018.

UPDATE at 3:40 p.m.: The motion to proceed passed, with Vice President Pence casting the tie-breaking vote. Two Republican senators, Susan Collins of Maine and Lisa Murkowski of Alaska, voted no. The Senate now moves on to ... whatever comes next.