There are a lot of Republicans who will have a hand in what happens next, and not just McConnell and Majority Whip John Cornyn, although they're definitely important. Caitlin Owens has been watching this for a while, and here's her list.
The chairmen: Lamar Alexander, Health, Education, Labor and Pensions Committee; Orrin Hatch, Finance Committee; Mike Enzi, Budget Committee.
Why: They're the experts — and Enzi will be especially important since everything they do has to comply with budget "reconciliation" rules.
The Medicaid caucus: Rob Portman, Pat Toomey, Cory Gardner, Shelley Moore Capito, Lisa Murkowski, Tom Cotton and Bill Cassidy.
Why: These members are from states that expanded Medicaid under the Affordable Care Act, and many of them spoke out against proposed cuts in an early version of the House bill. Portman is looking into an amendment that would create a more gradual phaseout of the expansion.
The conservatives: Ted Cruz, Mike Lee and Rand Paul.
Why: These members — particularly Cruz and Lee — are going to be big about states' rights. And Senate Republicans can't lose more than two votes, or the bill dies.
The 2018ers: Dean Heller and Jeff Flake.
Why: Both are from states that expanded Medicaid and are up for reelection next year.
Leadership: Senate Republican Conference chairman John Thune and Senate Republican Policy Committee chairman John Barrasso.
Why: They're both heavily involved in the effort. Thune has been working on an amendment to the House bill tax credit for weeks. Barrasso, a doctor, has led the caucus's anti-Affordable Care Act messaging for years.