"We'll have the votes. This will pass," House Majority Leader Kevin McCarthy, Republican, California, vowed on Thursday morning.
Democrats, meanwhile, predicted that the measure would be devastating for Americans' healthcare coverage but also, on a political level, for Republicans who voted for it.
House Minority Leader Nancy Pelosi, Democrat, California, noted that many Americans can't name their member of Congress, but that Thursday's vote is set to capture the nation's ire.
"You will glow in the dark on this one," Pelosi warned. "So don't walk the plank, especially unnecessarily."
The vote caps a haphazard debate that included few public hearings and the hasty revision of key sections of the bill during closed-door meetings at both ends of Pennsylvania Avenue designed to secure votes from sceptical conservatives and moderates initially unwilling to support the legislation.
Despite more than six years of campaign pledges to undo the ACA and the recent changes to the legislation, several Republican lawmakers admitted on Thursday that they have not read the bill or ignored questions about their understanding of the bill that were shouted by reporters. Republicans have accused Democrats in the past of ramming their healthcare bill through without giving members a chance to absorb it; but on Thursday they insisted that they are not doing the same thing.
They argued that their healthcare bill is only several hundred pages long, compared with the Affordable Care Act, which ran to several thousand pages.
Democrats "put a 2000 page bill on the table they knew no one had time to read, and we're not doing that," said Rep. H. Morgan Griffith, Republican, Virginia.
"This is a rough and tumble exercise that the Founding Fathers anticipated," he added.
House Freedom Caucus Chairman Mark Meadows, Republican, North Carolina, said he was willing to abandon his previous demands that leaders allow hearings and discussion of the legislation because members had opportunities to weigh in on amendments over the past several days. The decision marks a significant shift for hardline Freedom Caucus members who have insisted that leaders give them ample time to read legislation and weigh in before a bill comes up for a vote.
"We've had members working with members to come up with real amendments that are getting adopted today," Meadows said. "I can tell you that I have read the bill no less than six times. If they haven't read the bill it is because they haven't spent the time to do that."
Republicans also disregarded the absence of a final cost estimate from the non-partisan Congressional Budget Office (CBO). Congress's official scorekeeper on how much the bill would cost and how many people would receive healthcare coverage. Several said that last-minute changes to the legislation won't significantly change the final estimates.
"We're still comfortable we're saving billions and billions of dollars," said Chris Collins, Republican, New York.
Though Republicans have for years spoken of repealing the ACA as a prime goal, the legislation would stop short of outright eliminating the 2010 healthcare law enacted by a Democratic Congress and the Obama administration. Nevertheless, it would make a significant dent in large portions of current law.
The bill represents an attempt to shift to a more conservative vision for the nation's healthcare policies. It would move from the federal government to states the power to set important health insurance rules. It would end the ACA's subsidies for most people who buy health plans through marketplaces created under the law, creating, instead, new tax credits with clear winners and losers. And it would rescind several taxes that have helped pay for the law, including ones imposed on Americans with high incomes, health insurers, medical devices and tanning salons.
The bill faces a steeper climb in the Senate, where widespread disagreement remains among Republicans about how to proceed on healthcare. First, the Senate's parliamentarian, or rules-keeper, cannot review the legislation and determine the rules of debate until the CBO submits its official estimate, which could take several more weeks to complete, according to congressional aides. That would mean that official Senate debate on the bill could not begin until June.
Even then, the issue of healthcare reform is expected to be treated much more sceptically by Republican senators.
"A bill, finalised yesterday, has not been scored, amendments not allowed, and three hours final debate, should be viewed with caution," Senator Lindsey O Graham, Republican, South Carolina, tweeted on Thursday ahead of the House vote.
Among many other concerns, GOP senators from states that have expanded Medicaid under the ACA have voiced concerns about rollbacks to that programme included in the House bill. A trio of conservative senators - Ted Cruz, Republican, Texas, Mike Lee, Republican, Utah and Rand Paul, Republican, Kentucky, who often buck GOP leaders - are another wild card. With just a 52-48 advantage over Democrats, Senate Republicans have a smaller margin for error than their House counterparts.
The House measure may run into other procedural roadblocks in the Senate. The original proposal initially left many of the ACA's insurance regulations alone, with the goal of ensuring it would pass muster with the Senate parliamentarian, but not all of them. The House's version of the bill would undercut the ACA's insurance regulations even more. That might make it difficult for Republican senators to pass the measure under a procedural manoeuvre known as "reconciliation", which is usually reserved for budget legislation.
The legislation does not eliminate the ACA's requirement that most Americans carry health insurance, but it would undercut that requirement by erasing the penalty for not having coverage. Instead, the bill would create a deterrent: enabling insurers to charge 30 per cent higher premiums for one year to customers who have had a gap in coverage of at least about two months.
In the week leading up to the vote, a tug of war has played out among different wings of the House GOP over how much power states should have over insurance regulations. In the end, the bill incorporates two features advocated by the hard-right House Freedom Caucus. One would allow states to eliminate parts of the ACA that require insurers to include specific "essential health benefits" in health plans sold to individuals and small businesses, and set their own coverage requirements or none at all. The other would let states get federal permission to let insurers return to their old practice of charging more to customers with pre existing medical problems, a practice that the ACA outlaws.
An amendment last week freeing states to drop the same-price requirement for healthy and sick customers produced a backlash among some in the GOP conference. In the end, the bill includes $8 billion intended to be spread over five years to states that back out of this part of the ACA.
Medicaid would also be transformed in two ways. For the 31 states that, under the ACA, have expanded the safety-net program to include people with slightly higher incomes, the government would immediately stop paying for any one new to enrol under the expansion and would eventually stop the extra money the ACA has provided for that purpose. And starting in a few years, Medicaid would end its half-century tradition as an entitlement program in which the government pays a certain share for each person who enrols, switching to a "cap" with a fixed amount per person, a change that would lessen federal funding.
Much of the recent contention among Republicans revolved around how to protect patients with expensive, pre-existing conditions, prompting several amendments to the bill. Energy and Commerce Chairman Greg Walden presented those changes as improvements to the bill, in a slide presentation on Thursday morning to his colleagues.
According to the slides, insurers could charge such patients more only if a number of conditions were met. States would have to get a waiver from the federal government and the individual would have to be uninsured and buying their coverage on the individual market.
No matter when and how Senate debate begins, House Republicans exhibited a palpable sense of relief Thursday that the issue is off their plates, at least for now.
"It wasn't fun," said Rep. Lou Barltrop, Republican, Pennsylvania.
Meadows, who struggled for weeks to rally his caucus around the measure, said the Senate will make changes he might not necessarily back.
Collins added that "only time will tell" whether the bill will have a chance in the House once the Senate changes it.
