A small but powerful group of conservatives warned House Speaker Paul Ryan (R-WI) on Wednesday that his job would be in jeopardy if he doesn’t hold firm on a conservative immigration bill that has little chance of passing in the Senate.

“It is the defining moment for this speaker,” said Rep. Mark Meadows (R-N.C.), the chairman of the conservative House Freedom Caucus. “If he gets it wrong, it will have consequences for him. It will have consequences for the rest of the Republican Party.”

The threat to Ryan’s speakership comes amid a frustrating series of losses for conservatives in the House, who on Wednesday reiterated their anger at Republican leaders for getting behind a spending deal last week that raises budget caps by $300 billion.

GOP congressional sources told The Daily Beast that Republican members are looking for the speaker to hold firm against any Senate bill that doesn’t match all four of President Donald Trump’s priorities. And they warned that Meadows’ threat is legitimate.

His counterparts in the House Freedom Caucus said they would rather do nothing than sign onto what they consider to be a flawed proposal from the Senate.

“The Senate surely knows how to ignore bills from the House, and I think we ought to be capable of ignoring bad bills from the Senate,” Rep. Warren Davidson (R-OH) said.

“There’s no time deadline on this. No deal is better than a bad deal—particularly something this important,” Rep. Ralph Norman (R-S.C.) said. “This is a watershed moment for all of us, in my opinion. And it’s worth fighting for.”

If this immigration battle dynamic seems familiar, it’s because it happened before—five years ago, to be exact.

In 2013 the then-Democratic-led Senate passed a bipartisan comprehensive immigration reform bill that the House never considered after then-Speaker John Boehner (R-OH) bowed to similar pressure from conservatives.

No matter what immigration bill the Senate can craft and vote on by Thursday—GOP leaders’ self-imposed deadline—the world’s most deliberative legislative body will be on its own island in Washington. With Democratic votes required in order to get the requisite 60 votes, the Senate can only pass a slimmer piece of legislation that does not include many of Trump’s stated priorities.

The House and the White House have, in response, said they’ll refuse to accept the bills being debated in the Senate because, with the exception of one that mirrors the White House framework, they don’t go far enough to meet Trump’s demands.

As a result, the entire episode could end with Congress’ failure to enshrine legal protections for DREAMers, in a repeat of the 2013 “gang of eight” debacle that saw the House refuse to vote on a Senate-passed broad immigration reform bill.

Senate GOP leaders argued on Wednesday that the onus is on Democrats to support the framework put forth by President Donald Trump—or risk a 2013 repeat.

“[Congress’ failure to act in 2013] is another good reason to take the president’s proposal seriously. I think the president’s support for the bill will improve the chances that Republicans in the House will vote for it,” Senate Majority Whip John Cornyn (R-TX) told The Daily Beast.

But two of Trump’s four immigration priorities—scrapping the so-called chain-migration and diversity visa lottery systems—would essentially curb legal immigration. Those provisions remain non-starters for Democrats and some Republicans, creating an impassable roadblock to 60 votes.

As the Senate’s free-for-all immigration debate continued to stall on Wednesday, a bipartisan group of 25 senators introduced a last-ditch compromise plan that includes some of Trump’s priorities but not all of them. It drew swift rejection from the White House and the House, where Republicans are nearly united around legislation that mirrors Trump’s framework.

“I know that the president wants a result, and my experience in the Senate is that you’re more likely to get a result when you have a bipartisan plan. And that’s what we’re seeking,” said Sen. Susan Collins (R-ME), who is among the more than two dozen senators who have coalesced around the new bipartisan plan. “We obviously care about the House and about the president’s position, but we’re the Senate. We have to get through this stage of the legislative process first.”

But it’s unclear if that proposal—which, as of Thursday afternoon, had not been put into legislative text—can even win over 60 senators. Meadows, for one, told The Daily Beast that the new bipartisan Senate plan is a “non-starter.”

It all comes as Congress is inching closer toward a March 5 deadline to enshrine legal protections for so-called DREAMers, those undocumented immigrants who were brought to the U.S. as children, while boosting border security. That deadline, though, could be extended as federal courts hear challenges to Trump’s decision to end the Obama-era Deferred Action for Childhood Arrivals (DACA) program.

Cornyn on Wednesday outlined a strategy whereby the Senate would officially consider Trump’s plan as its final vote of the week as a way to raise the stakes and, ostensibly, blame Democrats if they block the legislation.

“If it’s either that or failure, I think we’ll have a better chance of maximizing the votes and getting to 60,” Cornyn said.

Some senators have been pushing for a bipartisan proposal that can win over 70 or more senators, arguing that passing a bill with such a large majority in the Senate would put pressure on the president and, in turn, Ryan.

“They have to be responsible for their actions and for what happens if they don’t act,” Sen. Debbie Stabenow (D-MI) told The Daily Beast.