Barack Obama and vice president-elect Mike Pence will have a showdown on Capitol Hill on Wednesday as the gloves come off in the fight over US healthcare.

The president will address House and Senate Democrats over how to counter Donald Trump’s stated objective of repealing the Affordable Care Act, a cornerstone of his legacy. Strategies are likely to focus on aspects of Obamacare that have bipartisan support as well as exploiting Republican divisions over how to replace it.

Pence, meanwhile, will address a meeting with House Republicans and attend a lunch with their Senate counterparts. A new, Republican-controlled Congress convened on Tuesday eager to repeal Obamacare after years of opposition.

Wednesday will mark a poignant, high-stakes return to Capitol Hill for Obama, who in 2009 delivered a landmark speech to the House for fundamental healthcare reform that had eluded presidents for decades. In a sign of the bitter wrangling to come, at one point he was interrupted by Republican Joe Wilson, who shouted: “You lie!”

The White House claims that, despite teething troubles, Obamacare has been a singular achievement. It brought health insurance to 22 million people and, for the first time in US history, means that more than 90% of Americans are insured.

Press secretary Josh Earnest told reporters on Tuesday: “I know that particularly at this time when there’s a lot of discussion about the president’s legacy, some people might think well, the president’s very concerned about political capital that he’s invested in this and doesn’t want to see it all go away.

“That’s certainly true, but the president’s priority and the president’s motivation is rooted in looking out for the interests of the 22 million Americans whose healthcare would be taken away if Republicans repeal the Affordable Care Act.”

Obama is concerned about a devastating impact on Medicare, which protects millions of elderly people, and Medicaid, a programme for low-income Americans, Earnest added.

He said: “It’s not surprising to me that there are some Republicans who are now a little queasy about the prospect of the impact that repealing Obamacare would have on their own supporters, on people in their own congressional districts, because we know there are people all across the country who benefit from this law, who are protected by this law, whose lives have been saved by this law, and the prospect of taking it away is a question of life or death for some people.”

Earnest suggested that Obama would encourage Democrats to focus on aspects of the Affordable Care Act that have bipartisan support. An obvious example is consumer protection that prevents employer discrimination against people with a pre-existing condition. “They should be out there telling the stories of their constituents who benefit from this law.”

Barack Obama might encourage Democrats to focus on aspects of the Affordable Care Act that have bipartisan support. Photograph: Mandel Ngan/AFP/Getty Images

During the election campaign, Trump vowed to immediately repeal and replace Obamacare although, after meeting the president, he indicated that some parts might be preserved. He nevertheless nominated a health secretary, Tom Price, who is an ardent critic of the law.

And this week Trump tweeted: “People must remember that ObamaCare just doesn’t work, and it is not affordable – 116% increases (Arizona). Bill Clinton called it ‘CRAZY’” He added: “The Democrat Governor of Minnesota said ‘The Affordable Care Act (ObamaCare) is no longer affordable!’ – And, it is lousy healthcare.”

As promised, Republicans wasted no time getting down to business when the 115th Congress convened on Tuesday. Senate budget committee chairman Mike Enzi, a Republican from Wyoming, introduced a resolution that he touted as a “first step” toward repealing the president’s signature healthcare law.



The resolution includes “reconciliation instructions” that would enable Republicans to dismantle key provisions of the law with a simple 51-vote majority in the Senate. Using this budgetary maneuver, Republicans can undo enough of the law to render it functionally ineffective.



Addressing the Senate for the first time as minority leader, Chuck Schumer, of New York, said it was “not acceptable to repeal” the healthcare law and “throw our healthcare system into chaos and then leave the hard work for another day”.

In a statement, House speaker Paul Ryan applauded the resolution, saying it “sets the stage for repeal followed by a stable transition to a better healthcare system”.

He added: “Our goal is to ensure that patients will be in control of their healthcare and have greater access to quality, affordable coverage.”

However, unravelling Obamacare’s provisions, which offer tax credits for purchasing private health insurance and allow states to expand coverage of Medicaid, is complicated. It may be expedient to replace those provisions with other forms of healthcare coverage, but House and Senate Republicans are divided on how to go about it.

Some Republicans have conceded benefits from Obamacare, whereas others are fiercely opposed. Representative Steve King of Iowa said: “I’m for the complete, 100%, rip-out-by-the-roots repeal of Obamacare. I don’t want to leave any vestige of it behind, not one particle of its DNA in law.”

Trump has wavered on his campaign promise to “repeal and replace” Obamacare. In a meeting with Obama after his election, Trump indicated that he was open to parts of the law, especially the measures that bar insurance agencies from refusing to cover people with pre-existing conditions and allow young people to stay on their parents’ health insurance until they’re 26.



At Trump’s New Year’s Eve bash at his Mar-A-Lago estate in Florida, the president-elect thrilled the crowd when he said: “We’re going to get rid of Obamacare.”

A recent study by the Commonwealth Fund, which was analyzed by the Rand corporation, found that implementing Trump’s healthcare proposal would cause nearly 20 million people to lose insurance coverage in 2018. When people with no insurance are admitted to the hospital, the costs are often shifted to taxpayers.



On Tuesday morning, Kellyanne Conway, a top adviser to Trump, said that the replacement process would be seamless. Asked if someone currently covered under the healthcare would have healthcare after it’s repealed, she replied: “That is correct.”



“We don’t want anyone who currently has insurance to not have insurance,” Conway said on MSNBC’s Morning Joe. “Also we are very aware that the public likes coverage for pre-existing conditions. There are some pieces of merit in the current plan.”

Democrats are planning to launch an effort to mobilise grassroots support for Obamacare by explaining how its repeal would create a ripple effect hurting a majority of Americans.