The House of Representatives is poised to vote today on healthcare legislation that would repeal much of the Affordable Care Act, replacing it with a plan that medical experts warn will drive up the cost of medicine while leaving millions without health insurance. House Majority Leader Kevin McCarthy said, after an evening huddle with party leaders, that Republicans have enough votes to pass the bill. Today’s scheduled vote came after Republican Reps. Fred Upton of Michigan and Billy Long of Missouri emerged from talks at the White House saying they flipped from “no” to “yes” after winning an amendment that will provide $8 billion over five years to subsidize health insurance for people with pre-existing conditions.

Rep. Fred Upton: “I talked to the president yesterday afternoon. I told him I could not support the bill as it was then moving through the Rules Committee, without added protections for those with pre-existing illnesses, and, based on our discussions and the agreement on this amendment, can now be in a place where I can support the bill with such amendment.”

It’s unclear how far the $8 billion subsidy would go toward protecting patients with pre-existing conditions. Senate Minority Leader Chuck Schumer of New York compared the measure to giving cough syrup to a cancer patient. Major medical organizations and the AARP have warned the bill will cause serious harm to patients and drive up the cost of healthcare. The Congressional Budget Office has not had time to “score” the legislation—meaning the House will vote on a bill without knowing its projected impact. A CBO review of similar legislation in March estimated it would add 24 million people to the ranks of the uninsured.