The outcome of a vote on U.S. health-care reform scheduled for Thursday evening is likely to be largely influenced by another vote which is more than a year-and-a-half away, Brian Klaas, a professor at the London School of Economics has told CNBC.
The 2018 midterm elections will "loom large" as the U.S. House of Representatives prepares to vote on the Obamacare replacement bill, Klaas told CNBC Thursday, as undecided Republicans will have to be accountable to their constituents for where they fall on the controversial vote.
"This is potentially a poisoned pill. If they don't pass it, Trump looks incompetent. If they do pass it, they're going to have to answer to their constituents in 2018," said Klaas.
The American Health Care Act (AHCA), backed by President Donald Trump, seeks to reduce federal health-care spending by $337 billion within the next decade, which he claims is crucial in enabling his pro-growth reform agenda. However, it also threatens to leave 24 million people without health insurance over the same period.
"The main argument for this bill seems to be if we pass it we can move onto tax reform. But that's not what health care's about: Health care is about providing health care to people," he said.
"People who are getting a tax break in this bill are wealthy, and people who are losing health insurance in this bill are poor and disabled … That's going to be very hard to spin in poor districts, which many Republicans represent, in the 2018 mid-terms," he added.
The House of Representatives is currently divided on the vote. The Republican Party requires 215 votes for passage but NBC analysis Wednesday suggested that it could miss this by six votes.
However, concessions made late Wednesday evening, which reduce the set of minimum benefits health insurers are required to provide customers, are thought to have won favor from the House's conservative Freedom Caucus, bringing the vote closer.
The president reached out on Twitter early Thursday in a bid to gain additional backing for his agenda, asking supporters to call their representatives and urge them to vote in favor of the reforms.
Markets have been moving cautiously Thursday after suffering their first wobble under a Trump presidency on Tuesday, evidencing concerns that he may fail to follow through with his planned reforms.
Speaking Thursday, Roger Jones, head of equities at London Capital, told CNBC the shift indicated a need for "consolidation" after the market rally of recent months.