House Republicans are making another—and possibly final—attempt to repeal and replace the Affordable Care Act with the latest version of their replacement bill, the American Health Care Act.

A first iteration of the bill was pulled in March, after it had become clear that it would not garner enough votes to guarantee passage. Republicans then made a series of changes and amendments to the bill to win both moderates and conservatives over to the yes column, the most prominent of which was a significant reduction of protections for people with pre-existing conditions, something the ACA prevented. 

Speaker of the House Paul Ryan is again trying to drum up the 216 votes he needs for the bill, but all it would take is 23 Republican no votes would make the bill fail. And many Republicans have already publicly committed to opposing it. 

Keeping track of which Republicans will be voting "no" has become the job of dedicated reporters and news outlets, scouring Capitol Hill for any signs of GOP House members' intentions. It's also a fluid, constantly-shifting process, as names shift between the various lists. Between the lists put together by six news outlets, there are currently 18 GOP House members who are confirmed, solid "no" votes: 

• Rep. Mark Amodei (Nev.)
• Rep. Andy Biggs (Ariz.)
• Rep. Barbara Comstock (Va.) 
• Rep. Ryan Costello (Pa.) 
• Rep. Jeff Denham (Calif.) 
• Rep. Charlie Dent (Pa.)
• Rep. Dan Donovan (N.Y.) 
• Rep. Brian Fitzpatrick (Pa.)
• Rep. Jamie Herrera Buetler (Wash.) 
• Rep. Walter Jones (N.C.) 
• Rep. John Katko (N.Y.) 
• Rep. Leonard Lance (N.J.) 
• Rep. Frank LoBiondo (N.J.) 
• Rep. Thomas Massie (Ky.) 
• Rep. Patrick Meehan (Pa.) 
• Rep. Ileana Ros-Lehtinen (Fla.) 
• Rep. Chris Smith (N.J.)
• Rep. David Young (Iowa)

But the list is constantly changing. On Wednesday morning, two Republican House members who were confirmed no votes, Billy Long of Missouri and Fred Upton of Michigan, jumped back to the yes column after President Trump assured them that the AHCA will include funding for high-risk pools, an alternative form of funding that has been shown to be ineffective for protecting pre-existing conditions. At the same time, Florida's Carlos Curbello, who was leaning toward no, officially came out against the bill on Twitter.

Two other House members, Rep. Michael Turner (Ohio) and Rep. Daniel Webster (Fla.), are included on some lists (including the Hill and CNN) as solid no votes, but not on others. 

With such a small margin for error, Ryan must lean on Republicans who are either leaning no, are undecided, or have been unclear on their stance. The names on this list are of some debate, as the Washington Post lists 30, while the Hill has about 50. 

Time is also a factor. With a seven day recess set to begin Friday, May 5, and with the bill having only a 17% approval rating, the GOP is looking to pass the bill before House members head home to face angry constituents.