WASHINGTON >> A peeved President Donald Trump browbeat Republican opponents of his party’s reeling health care bill today, asserting that his predecessor’s signature overhaul has meant “death” and saying the Senate’s planned faceoff vote is their chance to keep their pledge to repeal it.

Senate Majority Leader Mitch McConnell said he’d call a vote Tuesday on beginning debate on the legislation. While a victory on that initial but crucial roll call seemed an uphill climb, some Republicans expressed a new optimism that it would prevail — though the measure’s ultimate fate still seemed gloomy.

McConnell, R-Ky., said he’s “made a commitment to the people I represent” to undo President Barack Obama’s health care overhaul, in what seemed a pointed reminder to Republican senators that they’ve made the same vow.

McConnell did not describe precisely what version of the GOP legislation senators would be voting on, though No. 2 House GOP leader John Cornyn of Texas said later that Republicans would discuss that at a private lunch before the vote. That omission has caused confusion and frustration among some Republican senators.

At the White House, Trump lambasted Democrats who helped enact the 2010 health care law and uniformly oppose the GOP attempt to scrap and rewrite it.

“They run out and say, ‘Death, death, death,’” Trump said, with a backdrop of families that he said have encountered problems getting affordable, reliable medical coverage because of Obama’s statute. “Well, Obamacare is death. That’s the one that’s death.”

Some Democrats have said the GOP repeal effort would lead to death for patients who lose coverage. The nonpartisan Congressional Budget Office has said various versions of the legislation would mean more than 20 million Americans would become uninsured by 2026.

But Trump focused many of his remarks on GOP senators. McConnell is nursing a slim 52-48 majority and the possible absence of Arizona Sen. John McCain, who’s battling cancer, which would mean two GOP defections would sink the measure.

“For Senate Republicans, this is their chance to keep their promise. Over and over again, they said, ‘Repeal and replace, repeal and replace.’ But they can now keep their promise,” Trump said.

At least a dozen Republican senators have publicly opposed or criticized the legislation, more than enough to kill it. That’s forced McConnell to step back twice from anticipated votes and to revise his bill in hopes of mollifying unhappy moderates and conservatives.

Moderate Sen. Susan Collins, R-Maine, remained opposed to beginning debate on any option McConnell has revealed so far, and other Republicans remained uncommitted. But senators and aides said talks were underway on issues including potentially giving states more leeway on using federal funds to help people losing Medicaid coverage.

“I think we’re going to proceed to debate,” Cornyn said, though he acknowledged about McCain, “It would help if he’s here.”

McConnell’s measure would uproot much of Obama’s law, eliminating its tax penalties on people not buying policies, cutting the Medicaid health care program for the poor and providing less generous health care subsidies for consumers.

Complicating McConnell’s task, Ohio GOP Gov. John Kasich said it would be a mistake for the Senate to move ahead Tuesday “and force a one-sided deal that the American people are clearly against.” Kasich’s stance could make it harder for wavering Sen. Rob Portman, R-Ohio, who’s criticized the measure’s Medicaid cuts, to back the legislation.

Yet in one possible sign of progress by leaders, Portman said it’s “not as important to me” to know what bill McConnell would move to if the Senate votes to begin debate.

Kasich panned the bill for a lack of “bipartisanship, transparency or open dialogue.” In a statement, the 2016 GOP presidential contender said Congress should take no action on recrafting the nation’s health care system until it can “step back from political gamesmanship and come together with a workable, bipartisan plan.”

Yet Portman and other undeclared Republican senators were also being pounded by the White House.

“Republicans have a last chance to do the right thing on Repeal & Replace after years of talking & campaigning on it,” Trump tweeted earlier Monday.

Trump’s contentious tone toward his own party underscored the high stakes as he tries avoiding the specter of Republicans sinking one of his top priorities.

Characteristic of his scattershot effort on his party’s health care drive, Trump also spent the morning tweeting insults at Democrats, the news media and his own attorney general, Jeff Sessions, about their handling of investigations into his 2016 campaign’s possible collusion with Russia.

Late in the day, Trump used an appearance at the National Scout Jamboree in West Virginia to joke about firing his health secretary, Tom Price. Saying that Price “better get” the votes to begin debate on the legislation, the president said, “Otherwise, I’ll say: Tom, you’re fired.” He also told the crowd it “better get” West Virginia Republican Sen. Shelley Moore Caputo, who has expressed reservations about the GOP bill, to vote for it.

In comments highlighting GOP tensions, Rep. Blake Farenthold, R-Texas, said it is “absolutely repugnant” that Republican senators aren’t following through on campaign promises to repeal Obama’s law.

Without naming them, he mentioned “female senators from the Northeast” and said, “If it was a guy from South Texas, I might ask him to step outside and settle this Aaron Burr style,” a reference to the firearms duel in which Burr killed Alexander Hamilton. In a later statement, he said the remark was “tongue in cheek.”

Sen. Susan Collins, R-Maine, has opposed the GOP replacement plan. Other Republicans expressing reservations include Shelley Moore Capito of West Virginia and Lisa Murkowski of Alaska.

Farenthold spoke Friday on 1440 KEYS radio’s “The Bob Jones Show” in Corpus Christi, Texas.