The GOP has until September 30th to pass an Obamacare repeal bill with only 50 votes. Normally such economically sweeping bills need 60 votes to pass the Senate, but Congress can use a process called reconciliation to repeal laws passed within a certain amount of time. For Obamacare, that time expires at the end of September, at which point full repeal will become nearly impossible due to support from Democrats. However, the rush to try and pass the Graham-Cassidy bill through Congress means the Congressional Budget Office won't have time to analyze important details like how much premiums might rise and how many people will lose their insurance before the vote.
The ruckus has caused several senators, including Lisa Murkowski of Alaska, to refuse to support the measure. Desperate to pass any form of Obamacare repeal, the bill's authors reportedly offered several states, including Alaska, the option to keep their Obamacare subsidies while the rest of the nation loses theirs.