(Bastien Inzaurralde/The Washington Post)

Republican critics of the Senate’s latest version of health-care legislation were energized after leaders postponed votes on the measure, yet another sign the bill’s fortunes are in limbo.

A vocal conservative opponent of the measure, Sen. Rand Paul, predicted the delay would strengthen critics’ position by giving them more time to mobilize against the bill.

“The longer the bill is out there, the more conservative Republicans are going to discover it is not repeal,” Paul (R-Ky.) said Sunday in an interview with CBS’s “Face the Nation.”

Paul said he spoke with President Trump on Friday and suggested the president support repealing the Affordable Care Act and deciding the details of a replacement plan later if the latest version of the bill does not pass.

Sen. Susan Collins (R-Maine) is surrounded by reporters Thursday on Capitol Hill. (Alex Wong/Getty Images)

Trump did not comment on health care over the weekend, even as his party faced new challenges in trying to advance its latest bill. Trump made no reference to health care Sunday in an angry morning tweetstorm about Hillary Clinton, the Russia controversy and other topics.

The lack of response from Trump came after Sen. John McCain (R-Ariz.) announced Saturday that he is recovering from a surgery and would be absent from votes, depriving Republicans of the support they need to advance the legislation. The development temporarily dashed McConnell’s hopes of wrapping up the health-care debate by passing a reworked version of the Better Care Reconciliation Act this week.

The White House also was largely silent about health care over the weekend. “We wish Senator McCain a speedy recovery,” Helen Ferré, White House director of media affairs, told reporters Sunday when asked about the Senate delay.

The bill experienced a separate blow on Friday and Saturday at a conference of governors in Providence, R.I., where, despite an energetic lobbying campaign, Trump administration officials failed to gain support from influential Republicans such as Nevada Gov. Brian Sandoval. Opposition from Sandoval and others will make it easier for undecided Republican senators from those states to vote no on the bill, potentially further endangering its prospects.

These setbacks are the latest in the GOP’s struggle to enact a bill to replace the Affordable Care Act and fulfill a campaign promise central to the party’s message over the past seven years. Despite unified control of Congress and Trump in the White House, disagreements within the GOP still threaten to cripple its effort to overhaul the health-care system.

The difficult political calculus facing Republicans was clear in a new poll released Sunday that showed that the public prefers the Affordable Care Act to the Republican health-care plan by a roughly 2-to-1 margin. Among Republicans, 59 percent preferred the GOP plan, compared with 11 percent who preferred the current law.

The same poll, conducted by The Washington Post and ABC News, found that a strong majority (63 percent) believes it is more important for the government to provide health coverage to low-income people compared with cutting taxes (27 percent). Among Republicans, 48 percent favored cutting taxes, compared with 39 percent who favored providing health coverage for low-income people.

The bill’s dramatic cuts to the Medicaid program are a significant concern for governors such as Sandoval as well as moderate senators such as Susan Collins (R-Maine).

Vice President Pence and other administration officials sought to allay these fears Friday and Saturday by arguing that the health-care bill shores up Medicaid’s finances to preserve the program for the future. They also played down the possible effects of the cuts.

“President Trump and I believe the Senate health-care bill strengthens and secures Medicaid for the neediest in our society,” Pence said in a speech to governors Friday. “And this bill puts this vital American program on a path to long-term sustainability.”

Collins strongly disagreed in an interview Sunday with CNN.

“You can’t take more than $700 billion out of the Medicaid program and not think that it’s going to have some kind of effect,” she said during an appearance on “State of the Union.”

“This bill imposes fundamental, sweeping changes in the Medicaid program, and those include very deep cuts that would affect some of the most vulnerable people in our society, including disabled children and poor seniors,” Collins said. “It would affect our rural hospitals and our nursing homes, and they would have a very hard time even staying in existence.”

Pence’s speech was criticized by Democrats, health-care advocates and even some Republicans for mischaracterizing the possible ramifications of the GOP bill.

During the same speech, the vice president went after Ohio Gov. John Kasich (R), a critic of the legislation, by suggesting that his state’s expansion of Medicaid left nearly 60,000 residents with disabilities “stuck on waiting lists, leaving them without the care they need for months or even years.”

The claim alienated many at the meeting, partly because waiting lists for Medicaid’s home- and community-based services were not affected by the program’s expansion under the ACA, and partly because many interpreted Pence’s remark as an overly aggressive shot at Kasich. The Ohio governor’s stance against the bill could shape the position of Sen. Rob Portman (R-Ohio), a pivotal vote for Republicans who is undecided on the current version. Some fear Pence missed an opportunity to woo Portman with his remark against Kasich.

Collins estimated Sunday that there are eight to 10 Republican senators with “serious concerns” about the bill. “At the end of the day, I don’t know whether it will pass,” she said.

Paul does not believe Senate Majority Leader Mitch McConnell (R-Ky.) has the votes to pass the legislation, he told Fox. “I don’t think right now [McConnell] does,” he said.

The administration was not interested in entertaining analyses — including one by consulting firm Avalere — that show potentially devastating consequences for states under the GOP bill. At a meeting Saturday morning with governors, Health and Human Services Secretary Tom Price and Seema Verma, administrator of the Centers for Medicare and Medicaid Services, worked to undermine that report and a forthcoming analysis by the Congressional Budget Office showing the legislation’s cost and insurance impact. This effort bore little fruit, with Sandoval and others showing no signs of being moved by the lobbying effort.

The Avalere study projected marked reductions in federal Medicaid funding to all 50 states, ranging from 27 percent to 39 percent by 2036.

The CBO report is expected Tuesday or later in the week.

Price defended the health-care bill on Sunday, saying it will be part of a longer reform effort.

“The bill itself is not the entire plan,” he told ABC’s “This Week.” “It is significant, and an important and integral part of the plan, but it’s not the entire plan.”

Sean Sullivan, Greg Jaffe and Philip Rucker contributed to this report.