The success -- or failure -- of the GOP’s vote will be the most significant test yet for both Trump and Republican leaders in Congress, who have very little to show by way of legislative accomplishments so far this year.

220 votes

On Wednesday night, the Trump administration projected confidence about the outcome. At a White House dinner with religious leaders, a Trump aide joined the dinner late, saying the count had reached 218, two more than needed to guarantee passage. The aide added that he thought the final tally would top 220 votes, according to two people who attended.

“We’re going to bring premiums down” and “get insurers back into the markets,” Representative Greg Walden, a Republican from Oregon, told MSNBC on Thursday morning. Walden was one of a handful of lawmakers who met with Trump on Wednesday about an amendment that would add $8 billion to help insure people with pre-existing conditions, a measure designed to encourage more lawmakers to vote for the bill. “I think we’re on the right track here.”

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Even if the bill manages to pass the House, it faces a very tough road in the Senate. At least eight Senate Republicans are strongly opposed to different elements of the measure, which also faces potential procedural hurdles.

Representative Alcee Hastings, a Democrat from Florida, warned Republicans during a House Rules Committee meeting to expect changes to the bill if it is taken up in the Senate.

“I think they take health security a little more seriously and it’s a more moderate body than we are, and so you can reasonably expect that when you pass this tomorrow on the slimmest of margins, you shall not see it again, and you will not see it in the form that it’s in,” Hastings said Wednesday night.

House GOP leaders would be relieved to hand off the Obamacare repeal challenge to the Senate, given the excruciating back-and-forth of the past few weeks. In late March, Ryan and Trump had to abruptly scrap a planned vote on an earlier version of the measure with less than 24 hours’ notice, after counts showed it headed to a defeat.

‘Law of the land’

That led Trump -- who made repealing Obamacare a cornerstone campaign promise last year -- to lash out at House members in the arch-conservative House Freedom Caucus for not supporting that bill. The embarrassment also was intense enough for even Ryan to accept publicly afterward that Obamacare remained “the law of the land for the foreseeable future.”

But Ryan and his lieutenants decided to try it again, after members were bombarded by phone calls from Trump and negotiated amendments with senior administration officials, including Vice President Mike Pence.

Since no Democrats are expected to back the bill, Republicans can only lose 22 Republicans if everyone in the House casts a vote.

“I think everybody’s still wondering, do we really have the votes?” Representative Daniel Webster of Florida said Wednesday night. Undecided for weeks, he said late Wednesday that he’d back the bill.

Webster’s own decision to back the bill was late in coming, only after he said he got assurances his concerns would be addressed about future funding for his state’s Medicaid-funded nursing home beds.

But far bigger developments have helped change the landscape from March’s vote scuttling. The biggest shift came two weeks ago when conservatives who had been insisting for a full Obamacare repeal said they’d accept amendment language that would allow states to apply for waivers from some Obamacare regulations.

Pre-existing conditions

One of those waivers applied to pre-existing conditions -- to allow state to apply for waivers to let insurers in their jurisdictions charge people with pre-existing conditions more if they have a gap in coverage. States would have to develop some method, possibly a high-risk insurance pool, to help sick people.

The changes won over a number of conservatives, but alienated some House Republican moderates. They warned the amendment could weaken a popular protection offered by Obamacare that has helped sick people gain insurance coverage they were otherwise denied, or couldn’t afford.

Other lawmakers were angry that the measure was being rushed through the House, without any hearings. Last-minute changes were negotiated in secret, and members were being pushed to vote before the Congressional Budget Office had time to offer estimates on how the revisions would affect the cost of the measure or how many people would lose coverage.

“This is not the way we should operate, we’re a deliberative body,” Democrat Jim McGovern of Massachusetts said during the Rules Committee meeting Wednesday night. “I think the whole process and the way this has been handled is an insult to the institution, and more importantly it’s an insult to the American people.”

Then, on Wednesday, influential moderate Republican Fred Upton of Michigan -- a former Energy and Commerce chairman -- reversed his earlier opposition and embraced the bill after a meeting with Trump.

Upton told reporters that he would vote for the measure because Trump and the leaders said they would go along with additional language he helped devise to boost funding for people with pre-existing conditions by $8 billion over five years.

Outside health-care experts suggested that $8 billion wouldn’t fill the shortfalls in the high-risk pools, but at least three other previous holdouts signed on as co-sponsors. “This amendment reinforces my commitment to ensuring coverage for Iowans with pre-existing conditions,” said Representative Dave Young of Iowa.

House Republican leaders later Wednesday were saying that had put them within only a handful more votes needed -- and by Wednesday night McCarthy was claiming the needed votes were there.

Skeptical moderates

Even so, several influential moderates -- including Representative Charlie Dent of Pennsylvania, a co-chairman of the centrist Tuesday Group -- said they remained publicly opposed. Moderates, many of whom come from swing-state districts, could pay a high political price if people in their districts lose coverage.

And a wide array of industry groups and health advocates remained opposed to the GOP measure, despite the Upton-led changes.

AARP, the influential lobby that advocates for older Americans, says it remains opposed to the GOP bill, posting in a tweet that the Upton amendment is an “$8 billion giveaway to insurance companies; won’t help majority of those w/preexisting conditions.”

Passage of the GOP measure is just an opening hurdle and doesn’t mean smooth sailing in the Senate. It remains well short of the 50 votes it would need for passage. A number of Republican senators are unhappy with an earlier Congressional Budget Office estimate showing it would result in 24 million more people without insurance within a decade and skyrocketing premiums for lower-income people, particularly those over the age of 50.

But those and other hurdles only loom if the bill gets to the Senate.

Defeat of the bill Thursday would not only likely put a legislative dagger in Obamacare repeal, but it also would leave Ryan in a weaker position as speaker, defied by his own members.

And in a week that saw Trump fail to obtain early money in a government spending bill for his promised border wall between the U.S. and Mexico, he would see another campaign promise thwarted.

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