WASHINGTON — They couldn’t pass a repeal of ObamaCare, or find the votes for a White House-backed replacement. So now Senate Republicans are lowering their sights and trying to unite behind a so-called “skinny repeal” that would merely undo just a few of the most unpopular elements of Barack Obama’s law.

The “skinny bill” is an admittedly lowest-common-denominator approach, and it may not even have the votes to pass. But as Republicans search for how to keep their years-long effort to repeal and replace “ObamaCare” alive, they’re coming to believe that the “skinny bill” may be the only option left.

“It still keeps it in play,” said Sen. Steve Daines of Montana. “It’s threading a needle at the moment, trying to get 51 in the United States Senate.”

The strategy emerged after Republicans barely succeeded earlier this week in opening debate on health legislation in the narrowly divided Senate, winning the procedural vote to do so thanks only to Vice President Mike Pence breaking a 50-50 tie.

Hours of debate followed, as well as a few amendment votes that starkly revealed Republicans’ divisions. On Tuesday, on a 57-43 vote with nine GOP defections, the Senate rejected a wide-ranging proposal by Majority Leader Mitch McConnell to erase and replace much of the Affordable Care Act. Then on Wednesday, a straightforward repeal measure failed 55-45 with seven Republicans joining Democrats in voting “no,” even though nearly identical legislation had passed Congress two years earlier.

At that time, Obama was in the White House and vetoed the repeal bill. But now, with President Donald Trump sitting in the Oval Office and itching to sign it, Republican senators demonstrated they didn’t have the stomach to go through with passing a measure that would end insurance coverage for more than 30 million Americans over a decade.

The “skinny repeal” measure has not been finalized, but senators say it could eliminate Obamacare’s two mandates — for individuals to carry insurance and for employers to offer it — along with an unpopular tax on medical devices, and perhaps contain a few other provisions.

The purpose of passing such legislation would be to get something, anything, out of the Senate, so that talks could begin with House Republicans who passed their own more comprehensive repeal-and-replace bill in early May.