U.S. Senate GOP leadership’s latest salvo to repeal the Affordable Care Act (ACA) would result in an additional 16 million people losing insurance, according to an analysis released Wednesday night by the Congressional Budget Office (CBO).

Senate Democrats asked the CBO to analyze the effect of a half-dozen provisions they expect Republicans to back in an as-yet-unseen repeal bill. The provisions include a repeal of the ACA’s individual and employer mandates and “defunding” Planned Parenthood. The CBO, a nonpartisan legislative scorekeeper, estimated the Republican provisions would hike insurance premiums by about 20 percent compared to current law, a Democratic aide told Politico.

The analysis comes as the Senate is expected to vote Thursday afternoon on what’s being called the “skinny” repeal bill. Or, as Senate Minority Leader Chuck Schumer (D-NY) put it in a tweet late Wednesday, the “secret bill.”

Meanwhile, ten Democratic and Republican governors sent a letter Wednesday urging Senate leadership to reject the “skinny bill,” saying it would raise premiums, speed the demise of individual marketplaces, and result in many hardworking families losing coverage. Among the signatories was Nevada Gov. Brian Sandoval (R), who appointed Sen. Dean Heller to an empty Senate seat in 2011 and is thought to have influence on Heller’s vote, as the New York Times reported.

The events cap a tumultuous few days for Senate Republicans. Now that Republicans control the White House and Congress, they’re proving unable to deliver on their years-long vow to get rid of the ACA, or Obamacare, a law under which millions have gained health care, health insurance, and essential benefits, such as maternity care and no-copay birth control.

“No matter what version of Trumpcare the Senate votes on, it’s still the worst bill for women’s health and needs to be defeated,” Kelley Robinson, National Organizing Director, Planned Parenthood Action Fund, said in a statement.

Republicans have a 20-hour window to debate a repeal bill under budget rules that prevent Democrats from a filibuster.

Speaking from the Senate floor on Wednesday, Sen. Bill Cassidy (R-LA) voiced his party’s failures, saying, “We are struggling to find a replacement for the Affordable Care Act.”

Earlier, seven Republicans joined Democrats in rejecting a repeal-and-delay measure. The bill included language to “defund” Planned Parenthood for one year by barring Medicaid patients from using their insurance at health-care providers that provide abortion care.

A draft circulating Wednesday indicated that Republicans had recently changed the Medicaid reimbursement threshold in the defunding language, and advocates suggested the change was intended to skirt a Senate rule, as Rewire reported. The Byrd rule requires 60 votes for provisions not directly tied to the budget—a higher bar than a 51-vote majority.

But Republicans failed to even marshal 50 votes.

On Tuesday, an attempt to “repeal and replace” the ACA died by a wide margin, as Rewire reported. The Better Care Reconciliation Act would have dropped 15 million people from Medicaid and left nearly 50 million uninsured, according to the CBO.

Nine Republicans rejected the measure, dooming its passage. Sen. John McCain (R-AZ), who took to the Senate floor Tuesday to rail against partisan discord, had claimed he would “not vote for the bill,” but did that very thing.