The Senate on Thursday rejected a bill that would restrict the Trump administration from funding a lawsuit challenging the constitutionality of the Affordable Care Act that is scheduled for oral arguments at the Supreme Court just days after the Nov. 3 election.

The 51-43 vote, which was forced in a rare parliamentary maneuver by Senate Minority Leader Chuck Schumer (N.Y.), is part of an effort by Democrats aiming to show that Republican claims about supporting protections for preexisting conditions ring hollow. The measure needed 60 votes to advance.

Several vulnerable GOP senators joined Democrats in voting to advance the bill, including Susan Collins of Maine, Cory Gardner of Colorado, Joni Ernst of Iowa, Dan Sullivan of Alaska, and Martha McSally of Arizona.

President Donald Trump has repeatedly tried to take away Obamacares guarantees of coverage for people with preexisting conditions. Most recently, he ordered the Justice Department to support a lawsuit advanced by Republican governors seeking to strike down the law in its entirety including its coverage guarantees for patients with preexisting health conditions and health insurance for millions of Americans.

Despite this, Trump claimed in his August speech at the Republican National Convention that we will always and very strongly protect patients with preexisting conditions.

Legal experts view the underpinnings of the lawsuit dubiously, but its outcome is a lot more uncertain now that Trump has nominated conservative Amy Coney Barrett to succeed Justice Ruth Bader Ginsburg on the Supreme Court. Democrats argue Barrett, who has argued against Obamacare in the past, is part of a Republican plan to kill protections for people with preexisting conditions.

Republican senators facing reelection this fall have tried to reassure voters that they support those protections which, like Obamacare, are broadly popular, even though theyve voted in the past to repeal the law. Some have even tried to downplay the threat to Obamacare in the courts.

The experts are saying its highly unlikely theyll overturn the ACA, Sen. Steve Daines (R-Mont.) said in a debate earlier this week, But Daines, who is facing a strong challenge from Montana Gov. Steve Bullock (D), voted on Thursday against cutting off DOJs support for the anti-Obamacare lawsuit.

Two other Republicans facing reelection joined Daines in voting to maintain DOJ support for the lawsuit: David Perdue of Georgia and Thom Tillis of North Carolina.

Senate Majority Leader Mitch McConnell (Ky.) moved to protect GOP senators from Schumers gambit on Wednesday by setting up a competing vote on a bill offered by Tillis that they say would maintain coverage for preexisting conditions in case the Supreme Court strikes down Obamacare. That bill, however, would not provide coverage of essential benefits and other protections found under the ACA.

Democrats opposed Tillis bill, dismissing it as a show vote designed by McConnell to protect Republicans facing reelection.

They all say, Oh, yeah, Im for protecting preexisting conditions. Theyll have a chance to show it.... lets see what they do, Schumer told MSNBC before the vote on his bill, which he secured in a surprise move that is usually only employed by the Senate majority leader.

Schumer accused Republicans who crossed party lines to support advancing his bill on Thursday of doing so merely out political expediency.

These senators are worse off today no matter how they voted because they flip-flopped. They were for the lawsuit and now three weeks before the election they try to say theyre for it, he said at a press conference.

The effort to jam Republicans with an embarrassing vote on health care ahead of the election is only the latest among Democratic hardball tactics in the fight over Trumps Supreme Court nominee. Senate Democrats know they cant stop Barretts confirmation as long as Republicans remain united behind her, but theyre doing what little they can procedurally to delay it as much as possible and punish GOP senators for advancing a nominee this close to the election.

Schumer has blocked Senate committees from meeting as scheduled and delayed passage of a short-term bill funding the government. Democrats are also expected to keep the Senate in session next week in hopes of keeping vulnerable Republicans off the campaign trail. McConnell, meanwhile, has responded by scheduling more votes on confirming judicial nominees.