House Republicans are mired in an uncertain succession scramble after Speaker Paul D. Ryan’s surprise decision to retire, with rank-and-file members fearing their majority is in peril and openly suggesting that a larger leadership shake-up may be necessary.

Ryan (R-Wis.) intends to remain as speaker until the end of his term, and his endorsement of the No. 2 House Republican, Majority Leader Kevin McCarthy (R-Calif.), was meant to quell persistent questions about McCarthy’s readiness for the top job. Ryan is doubling down on that message in the next two months, co-hosting high-dollar fundraisers with McCarthy in a bid to preserve GOP control of the House.

But interviews with dozens of Republican lawmakers over the past few weeks reveal a race that is more unsettled than the top leaders are publicly acknowledging, one that could remain fluid and distract lawmakers from a tough midterm election battle.

The biggest mystery surrounds the roughly three dozen hard-line conservatives who helped tank McCarthy’s last run for speaker, in 2015. They are poised to again use their leverage to install a sympathetic leader, or at least one willing to meet their demands.

Further complicating the race is the wild card of President Trump, who has a close relationship with McCarthy and whom most hard-liners are unwilling to challenge head-on. For now, Trump is being advised to let the process play out.

“The longer this takes, the more uncertainty there is,” said Rep. Frank D. Lucas (R-Okla.), a veteran lawmaker who has served under six speakers. “I’m one of those folks who believes whatever the outcome is, it needs to be quicker, not later.”

Ryan’s departure could unleash years of repressed ambition and cause a scramble up and down the leadership ranks. Younger GOP lawmakers, for instance, are pushing for a more substantial role, arguing that their generation has been sidelined from policymaking and communications.

“There needs to be change,” said Rep. Scott W. Taylor (R-Va.), a first-term former Navy SEAL who is among those favoring a shake-up. “There doesn’t necessarily need to be a change of leadership — not necessarily — but if there was a change in leadership, you would see a change.”

Despite the restlessness, there appears to be a limited appetite to force an immediate shake-up. Most Republicans said that Ryan has tamped down an initial push for a quick transition to a new leader, and the notion of an extended leadership race holds appeal for hard-liners who want to force a lengthy debate about the direction of the party and establishment-oriented lawmakers who are wary of picking a new leader before November’s results.

“It’s definitely not going to be a coronation,” said Rep. Mark Meadows (R-N.C.), chairman of the hard-right Freedom Caucus. “It’s a matter of who can make the compelling case that things are going to be different here in Washington, D.C. And generally speaking, moving everybody up one rung doesn’t necessarily support a different approach to Washington, D.C.”

In a signal that conservatives will not be ignored, Rep. Jim Jordan (R-Ohio), a Freedom Caucus co-founder, scrambled the leadership derby by openly considering a run of his own.

Jordan’s move heightened the sense that conservatives are treating the upcoming race as an opportunity to remedy grievances, nursed for years, about being sidelined inside the House Republican Conference — their bills and amendments killed, their committee requests denied and their policy ideas ignored.

“We want to have a system that treats all members equally, but the greater issue to me is doing what we said we would do,” said Rep. Jody Hice (R-Ga.). “We’ve got to have leadership to push that needle forward.”

“Doing what we said we would do” has emerged as a rallying cry for the GOP hard-liners — shorthand for pursuing conservative policies on immigration, spending and other issues that have been blocked by Democrats and moderate Republicans.

That has complicated McCarthy’s path to power. His bid to succeed Rep. John A. Boehner (R-Ohio) as speaker in 2015 was torpedoed by conservative opposition, clearing the way for Ryan’s ascent when Boehner resigned from Congress.

Now Ryan and McCarthy are trying to create the perception of a seamless transition, an image they will present to top GOP donors during May and June events for a top Republican super PAC and for a joint fundraising committee McCarthy chairs with Vice President Pence.

Key hard-liners have been careful not to rule McCarthy out as they plot their next moves in an unpredictable race. Members of the Freedom Caucus have made an informal agreement not to pledge support to any leadership candidate for now, to enhance their leverage.

Asked whether McCarthy or another House leader might be suitable for the speaker’s job, Rep. Louie Gohmert (R-Tex.) declined to say: “That’s what we’re talking about in the Freedom Caucus, and I’ve agreed to keep my powder dry and try to work on a joint decision.”

But because of the vagaries of House leadership elections, the conservatives have an incentive to cut a deal with the GOP’s future leader before the election — which could help McCarthy.

The hard-liners number roughly 40, accounting for about one-sixth of the total number of House Republicans. Most, but not all, are members of the Freedom Caucus, a rambunctious group that has gotten accustomed to using its leverage at high-profile moments — at one point, for instance, helping to derail a high-profile health-care vote last spring.

If Republicans keep the House majority, their top leader will become speaker — requiring a majority vote of all 435 members of the body. In that case, a Republican speaker will need the hard-line bloc’s votes, giving it leverage to demand concessions.

But if the GOP loses its majority in November, the party will instead elect a minority leader as its top official — which requires only a majority of Republicans, not of the House at large. The hard-liners would be left at the margins.

The dynamics, according to a senior GOP lawmaker who spoke on the condition of anonymity to describe his view of the situation, amount to a high-stakes game of chicken in which the hard-liners have less leverage than meets the eye.

Meadows said he was not worried about losing leverage if Republicans lose the majority, arguing that “the cry for change will increase.”

Meadows said he would be inclined to take a deal “only if you’re looking at something that really compels the American people to show up and say, ‘They’re going to do things differently in D.C.’ And I don’t know what that looks like right now.”

But outside groups are pushing the conservatives to be aggressive and remain wary of any accommodation with mainstream Republicans.

Adam Brandon, president of FreedomWorks, a network of grass-roots conservative activists that endorsed Jordan to succeed Ryan, said their influence stands to grow regardless of whether Republicans keep the majority.

“If you lose the majority, what you’re going to want is a leader who is able to actually connect with the grass roots and fire up the base,” Brandon said.

McCarthy appears to be settling in for the long game. He mostly has refused to speak publicly about the leadership race, and a spokesman declined to comment.

“He can’t push too hard,” said one McCarthy ally who spoke on the condition of anonymity to comment frankly about his thinking. “There’s no reason to cut a deal ahead of time, because these guys are notorious for moving the goal posts. But I’m sure he’ll be talking to them.”

And while many conservatives are not ruling McCarthy out, they say he has work to do to win their trust.

“He’s articulate. He’s sharp. He gets the issues,” said Rep. Randy Weber (R-Tex.), a Freedom Caucus member who has a good relationship with McCarthy. “Can he take us to the proverbial promised land, whatever that means? Not if people won’t work with him.”