Republicans racing toward a vote on their health care overhaul have hit another roadblock. The vote was supposed to happen this week, but it's delayed as Arizona Senator John McCain recovers from surgery to remove a blood clot.

Majority Leader Mitch McConnell can only afford to lose two Republican votes - Senators Susan Collins and Rand Paul have announced their opposition.

About a dozen others are on the fence including Senator Dean Heller who says he's still reviewing the revised bill.

"We're moving through it, there's a lot of moving parts at this point you can imagine over the weekend, lot of discussions are going on so at this point we're going to continue the discussions and see where we come out at the end of the day,” says Senator Dean Heller (R).

The White House says President Trump is working the phones and inviting senators here to win support for the measure.

The bill is not much different from the original: it would still end ACA's penalties for people who don't buy insurance, cut back an expansion of Medicaid and cuts to the entitlement program. Compared to the original version, the new measure includes several tax increases from the ACA that were eliminated in the original bill: a 3.8% tax on net investment income, a 0.9% Medicare tax and a remuneration tax. It also includes $70 billion more than the first draft to help cover state-based health care reforms and an additional $45 billion to help states combat the opioid epidemic.

Nevada Governor Brian Sandoval told the Associated Press he had been in regular contact with Heller to discuss the growing impacts of the Republicans' plan. 

"They set policy, but we're the ones who have to develop the budgets, develop the care, develop the plans, work directly with the people," Sandoval said. He said if money is reduced, governors will be left to decide among unpopular choices: "Raise a tax or limit coverage or change eligibility requirements" for coverage.

(CBS News contributed to this report.)