Sen. Rob Portman Robert (Rob) Jones PortmanMcConnell locks down key GOP votes in Supreme Court fight Romney undecided on authorizing subpoenas for GOP Obama-era probes Congress needs to prioritize government digital service delivery MORE (R-Ohio) on Thursday said he would back a "skinny" ObamaCare repeal bill, another sign of growing momentum for a fall-back healthcare option in the Senate.

Portman said he was backing the bill as a way to start a conference with the House, which approved a broader ObamaCare repeal-and-replace legislation.

I will support legislation to move this process to a House-Senate conference because I believe we need to repeal and replace Obamacare. — Rob Portman (@senrobportman) July 27, 2017

Portman is a key vote.

Republicans can only afford two defections on their legislation and get it through the chamber. Winning 50 votes would allow Vice President Pence to break a tie.

ADVERTISEMENT

GOP leaders have not revealed their scaled-down measure, but it is expected that it would repeal the employer and individual mandates from ObamaCare.

In another key provision to win conservative support, it would also block federal funding for Planned Parenthood, which provides abortion services.

The skinny bill could also cut ObamaCare’s prevention and public health fund, while adding money for community health centers, sources said.

It would not cut Medicaid, which has been a concern for Portman and other centrist Republicans.

However, by allowing the Senate to enter a conference with the House, it could lead to a bill that does. The House measure would end federal funding for Medicaid's expansion by 2020.

If the Senate does pass a bill, both chambers would have to approve what ever emerges from the House-Senate conference.

Alternatively, the House could also approve the Senate's skinny bill in such a situation, though this would fall short of the hopes many conservatives have for a full repeal of ObamaCare.

It's not clear when the Senate will get to a final vote.

Sen. Roy Blunt Roy Dean BluntThis week: Supreme Court fight over Ginsburg's seat upends Congress's agenda McConnell locks down key GOP votes in Supreme Court fight Murkowski: Supreme Court nominee should not be taken up before election MORE (R-Mo.) said a vote was possible on Thursday night, but it is also possible it could be pushed to Friday.

House Majority Leader Kevin McCarthy's (R-Calif.) office has warned House lawmakers that they should not immediately depart Washington on Friday in case the Senate does approve an ObamaCare repeal bill.

Defunding Planned Parenthood could be challenged by Senate Democrats, who could argue such a step doesn’t meet the strict guidelines for reconciliation — the fast-track budget maneuver Republicans are using to repeal ObamaCare because it avoids a Democratic filibuster.

Sens. Susan Collins Susan Margaret CollinsGraham: GOP will confirm Trump's Supreme Court nominee before the election Gardner signals support for taking up Supreme Court nominee this year Tumultuous court battle upends fight for Senate MORE (R-Maine) and Lisa Murkowski Lisa Ann MurkowskiGraham: GOP will confirm Trump's Supreme Court nominee before the election Gardner signals support for taking up Supreme Court nominee this year Tumultuous court battle upends fight for Senate MORE (R-Alaska) might vote against the measure if it includes the Planned Parenthood language, as they have previously expressed concerns over defunding the women's healthcare organization.

But Republicans could afford those two defections if the rest of their conference holds together, and Portman's support is a key ingredient.