A final GOP effort to dismantle the Affordable Care Act burst into view this week in the Senate, where leaders began pressuring rank-and-file Republicans with the hope of voting on the package by the end of the month.

The renewed push comes nearly two months after the last attempt to overhaul the law known as Obamacare failed in a dramatic, early-morning vote, dealing a substantial defeat to President Trump and Senate Majority Leader Mitch McConnell (R-Ky.) and prompting many to assume that the effort was dead.

The latest proposal would give states control over billions in federal health-care spending, repeal the law’s key mandates and enact deep cuts to Medicaid, the federally funded insurance program for the poor, elderly and disabled. It would slash health-care spending more deeply and would probably cover fewer people than the July bill — which failed because of concerns over those details.

The appearance of a new measure reflected just how damaging Republicans consider their inability to make good on a key campaign promise of the past seven years: to repeal and replace President Barack Obama’s signature domestic policy achievement.

But trying again brings its own perils. It remains far from certain that McConnell can marshal the 50 votes he needs to pass the measure. Already under fire from Trump for falling short in the earlier effort, McConnell could see his standing with the president and other Republicans suffer all the more if he fails again.

Sen. Bill Cassidy R-La.), left, and Sen. Lindsey O. Graham R-S.C.) are two of four sponsors of a fresh effort to replace the Affordable Care Act. (Pablo Martinez Monsivais/AP)

Even Republicans who support the bill, including its chief sponsors, Sens. Bill Cassidy (La.), Lindsey O. Graham (S.C.), Dean Heller (Nev.) and Ron Johnson (Wis.), acknowledged the uncertainty of the moment. And McConnell has not committed to bringing the bill to the floor.

“I just told Bill Cassidy he’s a grave robber,” said Sen. John Thune (R-S.D.), one of McConnell’s top lieutenants. “This thing was six feet under, and I think he’s revived it to the point where there’s a lot of positive buzz and forward momentum. But it still comes down to, in the Senate, getting 50 votes.”

Still, the fresh flurry of activity marked the most serious attempt since the failed July vote to revive the long-standing Republican pledge to undo a law that has been vilified on the right. Among those joining the effort is Vice President Pence, who has been making calls to GOP senators and governors in support of the bill, according to a senior administration official who spoke on the condition of anonymity to describe the vice president’s private talks.

Part of the hurry results from the need to act before Sept. 30, when procedural rules expire that allow the Senate to pass legislation related to taxes and spending with a simple majority — and without any Democratic votes.

For McConnell, the path forward is politically perilous. His relationship with Trump has grown toxic since the July vote, prompting the president to approach leading Democrats to discuss a tax code overhaul as well as a potential deal protecting undocumented immigrants brought to this country as children.

Another failure for McConnell could embolden Trump and Democrats to continue working with each other.

But if the embattled Senate leader can shepherd a health-care bill to passage, sending the effort to fulfill a core Republican promise over to the House, he could set himself on a path to restoring his footing in other talks. Such an outcome could also help Republican senators who are facing reelection campaigns in 2018 and coming under increasing attacks from insurgent conservative challengers over the failure to repeal Obamacare.

In addition to the political turmoil, the unexpected return to health-care legislation has put the nation’s insurance industry in a state of uncertainty. After concluding that the effort was all but dead in July, some GOP senators reached out to Democrats to try to shore up the insurance marketplaces created under the ACA.

Now, industry officials must once again prepare for the possibility of a fresh and dramatic overhaul.

Cassidy has stopped short of predicting that his bill will pass, telling reporters that his goal was to write legislation that sets a marker for conservative health-care policy.

“We’re trying to set up good policy,” Cassidy said Sunday on NBC’s “Meet the Press.” “Whether it’s done now or later, the good policy will still be there.”

With Democrats united firmly against the bill, Senate GOP leaders can afford to lose only two of 52 Republican votes, enabling them to pass the measure with a tiebreaking vote from Pence. They lost three in the July vote: Sens. John McCain (Ariz.), Lisa Murkowski (Alaska) and Susan Collins (Maine).

None of those three committed to voting for the bill Monday, expressing reservations if not outright opposition.

“We need more information. I need to talk to the governor again,” said McCain, whose home-state governor, Republican Doug Ducey, endorsed the bill Monday. Ducey had also endorsed the previous bill, so his current stance is not necessarily a clue as to what McCain will do.

McCain warned against rushing ahead. “We just need to have a regular process rather than, ‘Hey I’ve got an idea, let’s run this through the Senate and give them an up-or-down vote,’ ” he said.

Murkowski said she was trying to learn more about the proposal’s impact on Alaska and consulting with her governor. On her way to McConnell’s office Monday afternoon, she wouldn’t say whether she was leaning for or against the bill.

Collins, who is seen by many Republicans as the strongest opponent of replacing the ACA, said Monday that she worries that millions could lose coverage under the new plan.

Adding to the challenge for Republican leaders: Sen. Rand Paul (R-Ky.) said Monday that he is a firm no at this point.

“I think this is a game,” Paul said. “I think this is a game of Republicans taking money from Democratic states. What happens if Democrats take power back?”

The proposal would slash health-care spending more deeply and would probably cover fewer people than the July bill, which failed precisely because of such concerns. Under the new bill, starting in 2021, the federal government would lump together all the money it spends on subsidies distributed through the ACA marketplaces and expanded Medicaid programs covering poor, childless adults who earn up to 133 percent of the federal poverty level.

This approach would generally result in less money for states that expanded Medicaid under the ACA and more money for states that didn’t. That’s because it would redistribute the money allotted to the 30 states that opted to expand Medicaid and spread it out among all 50 states.

Congress’s nonpartisan budget analyst said Monday that it is working to provide a “preliminary assessment” of the bill by early next week but will not estimate how the measure would affect health insurance premiums or the number of people with coverage until later.

The notice from the Congressional Budget Office angered Democrats, who warned that any attempt to vote on the GOP legislation poses a serious threat to ongoing negotiations on a plan to stabilize the current health insurance markets and strengthen subsidies for out-of-pocket expenses.

Senate Minority Leader Charles E. Schumer (D-N.Y.) dismissed the GOP plan as a way to hide a massive cut to Medicaid and criticized Republican leaders for moving forward without a complete assessment of who would be covered and how much it would cost.

“It would be outrageous for our Republican colleagues to vote for this bill without knowing its effect on people,” Schumer said. “That, whatever your ideology, would be nothing short of a disgrace.”

Democrats have virtually no way to stop the legislation from being approved if at least 50 Republicans unite. But Schumer vowed to use every procedural tool available to create roadblocks.

He warned Monday that the renewed GOP repeal push could upset talks between Senate Health, Education, Labor and Pensions Committee Chairman Lamar Alexander (R-Tenn.) and the committee's top Democrat, Sen. Patty Murray (D-Wash.), to offer a different approach that could pass the Senate with votes from both parties.

Even if the bill passed the Senate, it would face an uncertain outlook in the House.

“It’s too early to tell whether all the Freedom Caucus guys will be supportive or not because we don’t know what amendments will get added to the Senate bill,” said Rep. Mark Meadows (R-N.C.), chairman of the House Freedom Caucus. The bill could also meet resistance from Republican lawmakers from states that expanded Medicaid, given the sweeping changes it proposes.

Republicans are on a tight deadline to vote — before Sept. 30 — if they hope to avoid being blocked by Senate Democrats. Senate budget rules allow some tax and spending measures to pass with 51 votes, instead of the 60 needed for most legislation, meaning the 52 Senate Republicans could pass a bill on their own. But those rules, which were written specifically to enable the health-care law, expire at the end of the fiscal year, and GOP leaders hope to write next year’s rules to focus on hoped-for changes to the tax code.

McConnell did not mention the health-care push when he opened Senate business Monday afternoon.

Sen. John Cornyn (R-Tex.), McConnell’s top deputy, said, “We’re having a serious discussion, but it’s still preliminary.”

Asked how the process of securing votes was going, he replied: “That’s one of the things I’m not talking about.”

Paige Winfield Cunningham, David Weigel, Abby Phillip, Mike DeBonis and Elise Viebeck contributed to this report.