This article originally appeared on Fortune.
President Donald Trump’s effort to roll back Obamacare gained momentum on Wednesday as Republican leaders scheduled a vote in the House of Representatives on Thursday on a fresh version of legislation.
House Majority Leader Kevin McCarthy expressed confidence the bill would pass and several moderate Republican lawmakers who previously had objections to the bill said they could now support it.
Keen to score his first major legislative win since taking office in January, Trump threw his own political capital behind the bill, meeting with lawmakers and calling them in an effort to cajole their support.
Trump, whose Republican party controls both the House and Senate, is seeking to make good on his campaign promise to repeal and replace Obamacare.
Aides said he worked the phones furiously.
Wavering moderate Republicans had worried that the legislation to overhaul President Barack Obama’s 2010 signature healthcare law would leave too many people with pre-existing medical conditions at risk of not having health coverage.
But the skeptical Republican lawmakers got behind the bill after meeting with Trump to float a compromise proposal that is still expected to face unanimous Democratic opposition.
The legislation’s prospects brightened further after members of the Freedom Caucus, a faction of conservative lawmakers in the House who played a key role in derailing the original version of the bill last month, said they could go along with the compromise.
But even if the House advances the legislation, it faces a difficult road in the Senate.
Millions more Americans got healthcare coverage under Obamacare, but Republicans have long attacked it, seeing it as government overreach and complaining it drives up costs.
Called the American Health Care Act, the Republican bill would repeal most Obamacare taxes, including a penalty for not buying health insurance. It would slash funding for Medicaid, the program that provides insurance for the poor, and roll back much of Medicaid’s expansion.
The latest effort comes after earlier pushes by Trump for healthcare reform collapsed twice, underscoring the difficulty of rallying together divided factions of the Republican party.
Earlier this week, prospects for the legislation appeared grim as several influential moderate Republicans said they could not support the bill because it did not do enough to make sure people with pre-existing conditions could obtain affordable health coverage.
Putting a spotlight on the concerns about pre-existing conditions, late-night talk show host Jimmy Kimmel made a tearful plea for retaining that provision in Obamacare as he recounted a medical emergency that arose with his newborn son.
Kimmel’s monologue about his son’s congenital heart condition was viewed nearly 19 million times on his show’s Facebook page and on Wednesday morning was the No. 1 trending story on YouTube.
Republican Representatives Fred Upton and Billy Long, who were part of a group of moderate lawmakers who met at the White House with Trump, said the president endorsed their plan to add $8 billion over five years to help cover the cost for people with pre-existing illnesses who could otherwise be priced out of insurance markets.
Describing Trump’s efforts to secure his support, Long said Trump told him: “‘Billy we really need you, man.’”
Representative Mark Meadows, chairman of the conservative Freedom Caucus, said the new language on pre-existing conditions was a “net plus” for garnering the votes needed to pass the healthcare bill.
Critics of the changes to the law, including several health policy experts, said the $8 billion could not be enough to cover the cost of coverage for the sickest patients.
Republicans did not await a new score from the nonpartisan Congressional Budget Office to see how many people would be insured under their revised plan and how much it would cost.
UNCERTAINTY FOR STOCKS
Health insurers, such as Anthem antm , UnitedHealth Group unh , Aetna aet , and Cigna ci , have faced months of uncertainty over healthcare’s future. So have hospital companies, such as HCA Holdings Inc and Tenet Healthcare Corp.
On Wednesday, Aetna said it will exit the Obamacare individual insurance market in Virginia next year, citing “growing uncertainty” and expected losses this year.
House Democrats rejected the latest change to the Republican legislation on Wednesday, saying it appears to protect patients with pre-existing conditions but some could still be pushed off their insurance in certain states and face higher costs.
“This is deadly,” House Democratic Leader Nancy Pelosi told a news conference. “No Band-Aid will fix it.”
Democrats have long thought their best chance of stopping the repeal would be in the Senate, where only a few Republicans would need to defect to stop the law from moving forward.