Only 10 senators voted for the second measure, a symbolic proposal known as the Heller amendment.
Johnson, who has been critical of Senate GOP leaderships' handling of the process, was the last Senate Republican to cast their vote on a procedural motion that allows the debate to move forward. They're making plans to try to pass a narrowly focused bill undoing just a few of the most unpopular elements of Barack Obama's landmark health care reform law. Rand Paul introduced the amendment - within two years, and come up with a replacement plan in the meantime.
This measure, which is expected as Senate Majority Leader Mitch McConnell's last-ditch effort, would enact no new measure and limit repeal only to Obamacare's individual mandate, possibly along with the employer mandate and some taxes which Republican legislators oppose.
Nine Republicans crossed party lines and voted against it. White House Press Secretary Sarah Huckabee Sanders said Wednesday that President Trump was encouraged by the progress Republicans were making on the issue, and that the White House hopes to see a breakthrough in the coming days.More news: Deaths at Israeli Embassy in Amman Come as Jerusalem Seethes
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Because Republicans hold a narrow 52-48 majority in the Senate, they can only lose two votes because Vice President Mike Pence would serve as the tiebreaker.
"To every member of the Senate I say this: The American people have waited long enough".
Democrats argue that Obamacare brought coverage to millions of uninsured US residents, and analysis of various versions of the Republican proposal would put the number of people left uninsured at north of 20 million.
Still, the path toward repealing and replacing the health care law remains uncertain. If a compromise is reached, it's back to the Senate and House to vote on it.
The non-partisan Congressional Budgetary Office (CBO) found the bill would strip 22 million Americans of health insurance over the next decade.