(Lee Powell,Rhonda Colvin,Victoria Walker,Monica Akhtar/The Washington Post)

Senate Majority Leader Mitch McConnell (R-Ky.) released a new proposal to overhaul the Affordable Care Act on Thursday after spending three weeks reworking it to win over wavering lawmakers on the right and in the center.

But within hours, it was clear that Senate leaders still didn’t have the votes to fulfill their long-standing quest to replace former president Barack Obama’s 2010 health-care law.

The new draft would lift many of the ACA’s regulatory requirements, allowing insurers to offer bare-bones policies without coverage for services such as preventive or mental-health care. It would also direct billions of dollars to help lower- and middle-income Americans buy plans on the private market.

However, the draft leaves in place deep proposed cuts to Medicaid — and at least three Republicans quickly signaled opposition to the bill, casting doubt on McConnell’s plans to pass the bill next week.

What the Senate bill changes about Obamacare

“The revised Senate health-care bill released today does not include the measures I have been advocating for on behalf of the people of Arizona,” said Sen. John McCain (R-Ariz.) in a statement, adding he planned to offer amendments to change it.

The GOP’s continuing push — and continuing struggle — to make good on a campaign promise it began invoking seven years ago to “repeal and replace” Obamacare reflected the peril Republicans face whether they pass a bill or not.

On the one hand, the ACA has provided medical coverage for millions of Americans — and has grown more popular as a result. Moderate Republicans remained concerned Thursday that the new proposal would make insurance unaffordable for some ­middle-income Americans and throw millions off the rolls of Medicaid, the public insurance for disabled and low-income Americans.

Yet conservatives continued to push for a more wholesale rollback of the ACA — highlighting the danger for all Republicans of failing to achieve a promise most of them made on the campaign trail.

“The new Senate health care bill is substantially different from the version released last month, and it is unclear to me whether it has improved,” Sen. Mike Lee (R-Utah), a conservative who has pushed for a full Obamacare repeal, said in a statement. “I will need time to study the new version and speak with experts about whether it does enough to lower health insurance premiums for middle class families.”

Looming even larger was the reality that Republicans, despite their control of both chambers of Congress and with President Trump in the White House, have made little progress on an ambitious agenda that McConnell had hoped to move on to next week after a vote on the health-care bill. Among their goals are major tax legislation, raising the debt ceiling and passing a defense authorization bill.

Republican leaders seemed to acknowledge Thursday the difficult path ahead, with several speaking privately about internal divisions on how to pass the bill — and to prevent further defections.

Which GOP senators have concerns with the health-care bill

“We will have the votes when we start voting,” said Senate Majority Whip John Cornyn (R-Tex.).

McConnell’s new draft was the result of weeks of negotiations with conservatives and moderates. For those on the right, the plan incorporated a proposal from Sen. Ted Cruz (R-Tex.) allowing insurers to offer minimalist policies as long as they offer more-comprehensive ones as well. Cruz said the provision would give consumers greater choice and lower-cost premiums.

For those in the center, the new proposal would spend an additional $70 billion offsetting consumers’ costs and $45 billion to treat opioid addiction.

Republicans financed these changes by keeping a trio of Obamacare taxes targeting high earners — a 3.8 percent tax on net investment income and a 0.9 percent Medicare payroll tax on individuals making $200,000 a year or couples earning $250,000, along with a tax on insurers with high-paid executives. Lawmakers such as Sen. Bob Corker (R-Tenn.) said repealing those taxes would give too much relief to the wealthy at the expense of the poor.

The new measure has won Cruz’s backing, but Sen. Rand Paul (R-Ky.), another conservative who said the measure still does not do enough to unravel Obamacare, remained opposed to voting on the bill, as did centrist Sen. Susan Collins (R-Maine).

“My strong intention and current inclination is to vote no on the motion to proceed,” Collins told reporters, referring to the procedural vote required before the legislation can reach the Senate floor. Collins added that she hopes Senate Minority Leader Charles E. Schumer (D-N.Y.) will be willing to work with Republicans to fix the legislation. “I have had numerous Democrats come to me and say they want to work with us on the bill,” she said. “I’m going to take them at their word.”

Even as McConnell negotiated with individual members, the outlook for the bill was complicated when Sens. Bill Cassidy (R-La.) and Lindsey O. Graham (R-S.C.) debuted an alternative proposal.

In a joint interview with CNN on Thursday, Cassidy and Graham said they would take the billions of dollars the federal government now receives in taxes under the ACA and direct that revenue to the states.

The plan did not appear to be gaining traction — Graham said he would vote to start debate on McConnell’s bill — but its introduction underscored the extent to which a growing number of GOP senators have started looking beyond the current effort, with diminishing confidence that it will prevail.

“I don’t see this as the end if this bill were not to pass,” Collins said. “I see it as the beginning of the kind of process that I would have liked to have seen in the first place.”

The surprise announcement from Graham and Cassidy came just before Senate GOP leaders released their revised health-care proposal.

The McConnell plan would allow Americans to pay for premiums with money from tax-exempt health savings accounts, an idea that many conservatives have pushed for — a tax break that primarily would benefit the upper middle class.

The plan’s proposed rollback of Medicaid expansion under the ACA, as well as a proposal to slow the overall growth of the program starting in 2025, gave a number of Republican moderates pause Thursday.

Sen. Rob Portman (R-Ohio), who came out against the original draft of the bill, said he was not yet willing to vote yes to move the bill to the floor. “I’m in the same position I’ve been in, looking at the language and looking forward to the analysis,” he said.

Cassidy and Sen. John Hoeven (R-N.D.) said they need to see the Congressional Budget Office score, due next week, before making a decision.

“We are going to look at it, read it, understand it and see the CBO score,” Hoeven told reporters. He said that he was encouraged by changes intended to help lower-income Americans but that, “at this point, I’m reserving judgment.”

In a sign of the challenge McConnell still faces to round up votes, he huddled Thursday afternoon in his office with Portman and Sens. Shelley Moore Capito (R-W.Va.), Dean Heller (R-Nev.) and Lisa Murkowski (R-Alaska). Those lawmakers hail from states that have extended Medicaid under the current law to cover able-bodied, childless adults. Capito, who opposed the earlier bill, said in a statement she still has “serious concerns” about the revised draft.

With Vice President Pence prepared to cast a tiebreaking vote and no Democrats expected to support the bill, Republicans need the support of 50 of their 52 members to pass the legislation.

Senate leaders and Trump officials are aware that moderate Republican holdouts may be the bill’s biggest threat.

Seema Verma, administrator of the Centers for Medicare and Medicaid Services, made a presentation to a group of Republican senators from Medicaid-expansion states Thursday afternoon. She promised to do everything possible to minimize the number of uninsured, by giving states maximum flexibility in how they could use some of the money from the bill’s $182 billion state stabilization fund.

Nearly 15 million Americans would lose their Medicaid coverage by 2026 under the Senate bill, according to the CBO. Verma sought to minimize that outlook, saying states could use the stabilization funding to heavily subsidize private coverage for these Americans — even though the size of the fund does not come close to the bill’s $772 billion in cuts to the program over the next decade.

Cruz said the new bill was a “substantial improvement” over the first version and argued that a focus on reducing premiums was the best way to unite fractured Republicans. He touted his proposal as a means of accomplishing both.

“It’s not what the federal government mandates you have to buy — it’s your choice what health insurance is the best for you and your family,” Cruz said.

Critics, including insurers, say that providing the option of skimpier plans would draw younger, healthier consumers into a separate risk pool. That development would drive up rates for the Americans buying more-comprehensive coverage on the individual market, which could in turn destabilize the entire market.

The revised bill would establish a $70 billion fund to subsidize insurers providing both kinds of plans “for the associated costs of covering high-risk individuals,” according to a GOP summary of the bill. It would also allow individuals buying catastrophic plans to get a federal tax credit if they would be otherwise eligible, which is now barred under current law.

Larry Levitt, senior vice president for special initiatives at the Kaiser Family Foundation, said in an interview that “healthy people could end up with much lower premiums” on the private insurance market, though the proposal’s regulatory changes could upend coverage for those with costly medical conditions.

“There are many provisions in this bill that destabilize the individual insurance,” he said. “Then it attempts to restabilize it by funneling an enormous amount of money to insurers.”

The Senate bill also includes a limited exemption for members of Congress, which Republicans said was due to procedural limitations in Senate budget rules. Cruz introduced a measure to strike the exemption Thursday afternoon, saying in a statement, “While this exemption was included in the Senate health care bill out of procedural necessity, we must still be diligent in ensuring that Members of Congress are treated just like other Americans under this law.”

Senate leaders are leaving themselves the option of jettisoning the Cruz proposal after they get the nonpartisan CBO score, which will gauge the Cruz amendment’s impact on the budget and the overall number of uninsured.

Cornyn said Thursday that he expects the CBO will release two scores for the bill but would not confirm what those scores would include or when they will be released.

“We are expecting a CBO score, but I can’t tell you exactly what the format will be,” Cornyn told reporters, adding that the Cruz amendment would be scored.

Paige Winfield Cunningham and David Weigel contributed to this report.