The bill largely mirrors the House measure that narrowly passed last month but with some significant changes. But in the week since, Senate Republicans are quickly coming up against some of the same obstacles that dogged House Republicans - and dealing with new problems of their own creation.
McConnell wants it passed before Senators depart for the July 4 recess.
Noting that President Donald Trump called the legislation passing the House "mean", Durbin said of the Senate proposals, "you can put a lace collar on a pit bull, and it's still a mean dog".
Senate Republicans launched their plan for shriveling Barack Obama's health care law Thursday, edging a step closer to their dream of repeal with a bill that would slice and reshape Medicaid for the poor, relax rules on insurers and end tax increases on higher earners that have helped finance expanded coverage for millions.
McConnell has very little room for error - he can only lose two Republican votes and still pass the bill.
U.S. Sen. Bernie Sanders, I-Vt., issued a series of tweets and said, "We must do everything we can to preserve our democracy and oppose the current drift toward authoritarianism Trump represents".
Trump echoed these calls on Wednesday at a campaign rally in Iowa. "I'd find it hard to believe we'll have enough time", he said, adding that if he did not get enough information, "I won't be voting yes". "A plan with heart, but Obamacare is dead". "They took a House bill that that didn't reduce the cost of premiums, that didn't expand health coverage for all, that didn't protect people with pre-existing conditions and that nobody liked, and nobody wanted, and doubled down on it".
McConnell is pushing toward a vote next week but Paul's stance throws that into question. "I've made leadership well aware of the fact that I need information to make a final decision, and if I don't have the information to justify a yes vote, I won't be voting yes". It has come under widespread criticism from Democrats and helped prompt some moderate House Republicans to vote against the measure.
Lawmakers will be "looking to see if there are things that we can do to refine it, and make it more acceptable to more members in our conference, to get to 50", Senator John Thune said. That's a fundamental change; now the program is "open-ended", meaning funding increases as need increases.
Release of the 142-page proposal ended the long wait for one of the most closely guarded bills in years.
Under Obama's law, "many of those people would have gotten much more generous plans", she said.
The nonpartisan Congressional Budget Office said the House bill would cause 23 million people to lose coverage by 2026.
Some of the Senate bill's provisions could be political land mines, with individual senators' reactions crucial to determining whether or not the Affordable Care Act, popularly known as Obamacare, survives a Republican attack that has been underway since its passage in 2010.
What will happen to Medicaid and the people who rely on it? This is a concession to moderates, who weren't pleased that the House version would end the enhanced support for new enrollees in 2020.
The AHCA makes huge cuts to Medicaid - a program that covers 1.2 million Pennsylvanian children and is a lifeline that keeps our hospitals and doctor's offices running and ensures our most vulnerable residents can get care.
Like the House bill, the Senate measure would block federal payments to Planned Parenthood.