“Republicans now are dealing with the fact that they’ve built a castle on a foundation of lies,” Rep. Jim Himes (D-Conn.), who chairs the moderate New Democrat Coalition in the House, said in an interview. “The last thing we would want to do is get in their way.”

House Democrats will link arms with former Vice President Joe Biden on Wednesday for an Obamacare rally that looks more like an Irish wake, celebrating the health care law as they avoid even trying to amend Ryan’s bill.

To be sure, rank-and-file House Democrats will be making a lot of noise leading up to the House repeal vote Thursday. Democrats will be giving floor speeches blasting the Republican plan on a regular rotation. And members will have access to two “spin rooms” in the Capitol that allow them to talk to local media and record Facebook live videos opposing the GOP bill.

But Democratic leaders are discouraging members from offering amendments when the Rules Committee meets to debate the GOP health care bill on Wednesday. And on Thursday, Democrats don’t plan on offering a “motion to recommit,” the procedural move typically proposed by the minority to delay passage of a bill on the floor.

Their thinking, according to multiple sources, is that offering amendments to improve the bill, if adopted, would give wobbly Republicans cover to vote for the repeal — hampering Democrats’ chances of tanking the proposal before it even reaches the Senate.

Democrats have reason to be hopeful for an Obamacare collapse that could devastate Trump’s domestic agenda and put the GOP’s House majority at risk next year. Republican senators are openly split over whether to move the House bill to the left or right, and they may have only a week to consider it on the floor under Senate Majority Leader Mitch McConnell’s jam-packed schedule.

One Republican whose state has expanded Medicaid under Obamacare — and thus stands to lose a lot of money under repeal — walked onto a senators-only elevator Tuesday unsure how to answer questions about “whether I would support the deal” on health care.

“How can I know what the deal is until we see the deal?” the GOP senator asked a Democratic colleague.

While Trump made a hard sell with House Republicans on Tuesday, warning them to fall in line or else, he’s already had a tougher time with Senate Republicans — most of whom will never have to share a ballot with the president again. Even the dozen GOP senators elected in 2014 on widespread vows to dismantle Obamacare are among the biggest skeptics of Ryan’s repeal bill.

McConnell, already sensing the battle he will face with Republicans in his chamber if Ryan can muscle through his repeal plan, fired off his own warning shots on Tuesday.

“I would hate to be a Republican whose vote prevented us from keeping the commitment we’ve made to the American people for almost 10 years now,” McConnell told the AP.

McConnell later disputed that his comment was threatening fellow Republicans, telling reporters that he’d made only a “statement of the obvious.”

The mounting internal tension has House Democrats optimistic about a GOP implosion.

“I am as positive as I can be ... that Speaker Ryan does not believe this bill will pass the Senate,” House Minority Whip Steny Hoyer (D-Md.) told reporters Tuesday.

But some Senate Democrats don’t share that enthusiasm. Sen. Brian Schatz of Hawaii said he was worried about quick passage of an Obamacare repeal unless public pressure can be sustained.

“The House is poised to pass an awful piece of legislation that no one understands in a hurry by a few votes and there’s no reason to assume that wouldn’t happen in the Senate as well,” Schatz said in an interview. “So we’ve got a real fight on our hands, and if anybody thinks we’ve got it won, they misunderstand the situation.”

“I’m not sure the House’s strategy should be depending on Mitch McConnell,” Sen. Chris Murphy (D-Conn.) said in an interview.

But House Democrats think GOP leaders in the Senate will have a much harder time changing the bill to appease tepid Republican senators.

“It’s not as simple as simply offering amendments which will make it more palatable,” Hoyer said, “because those amendments may be inconsistent” with strict Senate budget rules that allow McConnell to repeal Obamacare with a simple majority vote.

For Pelosi, the battle goes beyond just fighting to save Obamacare — and her legacy. Lawmakers and aides say the longtime Democratic leader has shown a disdain for Trump unlike any for a previous Republican leader.

Pelosi has blasted Trump publicly and privately, calling him “disgusting” and without “class” in recent meetings. Stopping one of Trump’s signature campaign promises dead in its tracks would be a fitting denouement for Pelosi, who has said the only reason she hasn’t retired is to protect Obamacare from being destroyed.

And Republicans’ failure to pass their health care repeal could also severely stunt other items on Trump’s legislative wish list, including tax reform and trade.

For House Democrats, the focused fight against GOP repeal efforts has been a welcome distraction for a caucus that has struggled to come together after months of soul searching and finger pointing following a disastrous election.

Even lawmakers like Wisconsin Rep. Ron Kind, one of four Democrats to publicly oppose Pelosi during the speaker’s election in January, says for now, the caucus is on the right path.

Trump “is sucking the oxygen out of the room right now,” Kind said. “Sometimes you need to just step back and sell them a little bit of rope and see if they go with it.”

Jennifer Haberkorn contributed to this report.