So when McCain, 80, announced that doctors in Phoenix removed a five-centimeter (two-inch) blood clot above his eye - a procedure that experts told United States media might be more serious than initially thought - Senate Majority Leader Mitch McConnell said he would "defer" the upcoming vote on the bill by at least a week.
A close vote had already been predicted for the Republican healthcare bill, with all Democrats and independents coming out against it and some Republicans opposed or undecided.
McCain, R-Ariz., had surgery Friday to remove a blood clot over his left eye. With Democrats united against the new health care bill, and two Republicans - one conservative and one moderate - already declaring their opposition, McConnell can not afford to lose a single vote. Susan Collins, R-Maine, doesn't want to proceed to the bill because it would actually address rampant Medicaid spending. McCain has expressed concern about the healthcare bill but has not said how he would vote.
"I've been involved with health care for 20 years as a physician", he said "It was in awful shape before Obamacare, got worse under Obamacare, and I predict that the fundamental flaw of Obamacare will remain with the Republican plan, and this is a big reason why I can't support it".
"Every day that the Senate doesn't repeal the Affordable Care Act and gut Medicaid is a day that makes it less likely they'll be able to pass it", said Ben Wikler, Washington director of the progressive group MoveOn that is opposing the bill.More news: Police Release Sketch Of Suspect In Delphi Murder Investigation
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The bill is not much different from the original: it would still end Obamacare's penalties for people who don't buy insurance, cut back an expansion of Medicaid and cuts to the entitlement program.
House Republicans are giving their Senate colleagues some space to get their health care bill through, but there are already some concerns surfacing about the changes to the bill that could be made through the amendment process and whether they could support the final product.
Asked on "Fox News Sunday" whether Mr. McConnell has the votes right now, Mr. Paul said, "I don't think he does". But the ability to regularly see a doctor, and the assurance that some preventative health care screenings will be covered at no additional cost, greatly increases the likelihood of catching the kind of warning sign that could be life-saving - as it may have been for McCain.
Collins said she's been in touch with members of the Trump administration about the bill, which she calls "a work in progress". More often than not, a blood clot "in this area would be a very concerning issue", he said. "The Senator is resting comfortably at home and is in good condition". Pathology reports are expected in the next several days. Last month, Senator John Cornyn said passing the bill is "not going to get any easier" with time, and Senator Lindsey Graham has said the bill "is not like fine wine; it doesn't get better with age". He previously had three other malignant melanomas removed, on his left shoulder, left arm and left nasal wall (removed in 1993, 2000 and 2002 respectively).
The Senate floor schedule is unclear now that health care is on hold.