The US House of Representatives has passed a Bill repealing Obamacare, but the Republican Party's seven-year effort could still flounder in the Senate.
Passing the Bill to repeal former President Barack Obama's signature domestic achievement would be President Donald Trump's biggest legislative win since he took office in January.
However, it is by no means a sure thing in the Senate, where the Republican majority is narrow and where lawmakers said the bill would face much greater scrutiny and skepticism.
The Democrats mockingly chanted "na-na-na-na, na-na-na-na, hey, hey, hey, goodbye" at the Republicans who'd voted for the American Health Care Act. The singing came as a reminder that many Republicans could be voted out of office by next year on account of supporting the repeal of Obamacare.
The vote in the House was 217 for, 213 against. No Democrats voted for it, and 20 Republicans crossed the floor to vote against it.
Former vice-presidential candidate Tim Kaine said millions would lose their health care if the Bill becomes law.
Despite controlling the White House and Congress, Republicans have found that overturning Obamacare - which they have long criticised as government overreach - is politically fraught, in part because of voter fears that many people will lose their health insurance as a result.
Democrats are hoping that the Republicans' vote to repeal Obamacare will spark a voter backlash in next year's midterm congressional elections.
Passed in 2010, Obama's Affordable Care Act expanded Medicaid, the government insurance program for the poor, provided income-based tax credits to help the poor buy insurance on individual insurance markets set up by the law, and required everyone to buy insurance or pay a penalty. Republicans have blamed it for driving up healthcare costs.
The Republican bill, called the American Health Care Act, would repeal most Obamacare taxes, which paid for the law, roll back the Medicaid expansion and slash the program's funding, repeal the penalty for not purchasing insurance and replace the law's tax credits with flat age-based credits.
An unusually emotional debate erupted on the House floor Thursday morning as Democrats blasted the bill, saying it would make insurance unaffordable for those who need it most and would leave millions more uninsured.
In a sign of the scrutiny it will in the upper house, Republican Senator Bob Corker told MSNBC there was no way the healthcare bill would receive a quick up-or-down vote in the Senate and predicted senators would spend "at least a month" studying it.
Mr Trump made overturning Obamacare a cornerstone of his 2016 campaign and has been frustrated as two efforts to push a Republican bill through the House failed in the last two months, a reflection of the difficulty of reconciling various Republican Party factions.
Wavering moderate Republicans had worried that the legislation would undo a popular aspect of Obamacare and leave too many people with pre-existing medical conditions unable to afford health coverage.
But the skeptical Republican lawmakers got behind the bill after meeting with Trump to float a compromise proposal, which would add US$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.
Democrats have long thought their best chance of stopping the repeal of Obamacare would be in the Senate. Republicans hold a narrow 52-seat majority in the 100-seat chamber.
Reuters / Newshub.