Despite optimism among Senate GOP leaders that they may be able to get a vote on their still-evolving version of a health care reform bill by the time they leave for the July 4th recess, at least one senior Republican is acknowledging it's more likely to take place beyond that date.

“It looks to me like it’s not going to be until next month sometime,” Senator John Cornyn, R-Texas, the second ranking Republican, told reporters Thursday.

The shift in timing might seem small but it’s significant because of the mandatory October 1 deadline for the bill to be on the president's desk that is imposed on health care legislation due to the use of a special legislative vehicle, known as reconciliation, that runs out at the end of the fiscal year. And because Congress is out of session for the month of August, time is tight.

The potential delay of a vote also demonstrates the challenges Republicans are facing in putting together legislative details that can attract the 50 GOP votes it would need to pass.

“I don’t think we’re any closer, I don’t think we’re any farther,” said Sen. John Boozman, R-Arkansas. “We’re trying to figure it out.”

One of the many sticking points is how to address the Medicaid expansion. Senators from states that have expanded the low-income health care program under the Affordable Care Act are reluctant to reduce benefits and kick people off its rolls. Senators from states that opted not to expand Medicaid are more supportive of a quick roll back that reduces the size and the scope of the program.

When Sen. Rob Portman, R-Ohio, who is protective of Ohio’s Medicaid expansion, was asked Thursday if they are any closer to an agreement on Medicaid, he simply responded, “Not necessarily.”

Sen. Lisa Murkowski, another member worried about her Medicaid population in Alaska, said Republicans “are still trying to figure out” how it will be addressed.

“We’re trying to figure out how we can make sure the assistance that has been there is able to continue,” Murkowski said.

There is some talk about a long wind-down of the Medicaid expansion. The House version of the bill immediately cuts off the expansion and ends it by 2020.

Discussions are also taking place about keeping some of the Obamacare taxes to help pay for the expensive components of the GOP bill, including an pool of money to help people with pre-existing conditions and subsidies to help people purchase insurance. But that’s a difficult sell for some conservatives.

When asked if he would support keeping Obamacare taxes, Sen. Pat Toomey, R-Penn., said he wouldn’t.

“I think we should repeal all of the Obamacare taxes,” Toomey said.

Sen. Orrin Hatch, R-Utah, and the head of the Finance Committee, which oversees the tax portion of the health care bill, said of the Obamacare taxes that he’d “like to get rid of them all if I can.”

But Sen. Tim Scott, R-S.C., said that senators need to be “open” to ideas they wouldn’t usually support.

“I think you have to remain open to what it takes to get 51 votes,” Scott said.

As for the path to 51, Republicans aren’t there yet. Sen. Lindsey Graham, R-S.C., said that he’s a bit more optimistic than he was at the beginning of the week where he said that it’s not likely Republicans can find a majority.

“(It’s) more promising than before but still problematic,” Graham said.

He added: “It’s hard and we’re divided.