WASHINGTON — Senate Majority Leader Mitch McConnell has finally unwrapped his plan for dismantling President Barack Obama’s health care law. Now comes his next challenge — persuading enough Republicans to back the measure and avert a defeat that would be shattering for President Donald Trump and the GOP.

McConnell released the bill Thursday, drafted after weeks of closed-door meetings searching for middle ground between conservative senators seeking an aggressive repeal of Obama’s statute and centrists warning about going too far. Erasing Obama’s law has been a marquee pledge for Trump and virtually the entire party for years.

The bill would cut and redesign the Medicaid program for low-income and disabled people, and erase taxes on higher earners and the medical industry that helped pay for the roughly 20 million Americans covered by Obama’s law. It would let insurers provide fewer benefits, offer less generous subsidies than Obama to help people buy policies and end the statute’s tax penalties on people who don’t buy policies and on larger firms that don’t offer coverage to workers.

“I am very supportive of the Senate (hash)HealthcareBill. Look forward to making it really special! Remember, ObamaCare is dead,” Trump tweeted late Thursday.

Shortly after the 142-page bill was distributed, more than a half-dozen GOP lawmakers signaled concerns or initial opposition. McConnell, R-Ky., has little margin for error: Facing unanimous Democratic opposition, “no” votes by just three of the 52 GOP senators would sink the legislation.

McConnell, eager to approve the legislation next week, indicated he was open to changes before it reaches the Senate floor. But he said it was time to act.

“No amount of eleventh hour reality-denying or buck-passing by Democrats is going to change the fact that more Americans are going to get hurt unless we do something,” he said.

Democrats said the GOP measure would take coverage away from people and raise their out-of-pocket costs, all in the name of paring taxes on the wealthy.

“This bill may change, but Republicans will only be putting lipstick on a devastating blow to Americans’ health care,” said Sen. Ron Wyden, D-Ore.

Four conservative senators expressed opposition but openness to talks: Ted Cruz of Texas, Kentucky’s Rand Paul, Mike Lee of Utah and Ron Johnson from Wisconsin. They said the measure missed delivering a GOP promise to Americans “to repeal ObamaCare and lower their health care costs.”

In an interview with Fox News Channel, Trump was asked about the four conservatives opposing the bill. “Well, they’re also four good guys, four friends of mine and I think that they’ll probably get there,” he said. “We’ll have to see.”

Sens. Dean Heller of Nevada, facing a competitive 2018 re-election battle, Rob Portman of Ohio and Shelley Moore Capito of West Virginia expressed concerns about the bill’s cuts to Medicaid and drug addiction efforts.