Paul Ryan's tenure as speaker of the House could end sooner than he thought, with legislative failures mounting and the Republican conference continuing to fracture.

Ryan has maintained that he will "run through the tape" and stay on as speaker until the new Congress arrives in January.

Republicans have grown uneasy with Ryan, as evidenced by House conservatives and moderates openly disobeying the speaker.

WASHINGTON — When House Speaker Paul Ryan informed the Republican conference in April that he would not seek reelection in 2018, he hammered in the point to his colleagues that he would "run through the tape" and hold the gavel until the new Congress arrives in January. The growing problem for Ryan is that the tape might be much closer than he thought.

Behind the scenes, potential replacements for the House GOP's top spot are strategizing and discussing options.

House Majority Leader Kevin McCarthy is the heir apparent, despite dropping out of the speaker's race in 2015, leading to Ryan's reluctantly taking the gavel. Ryan last month publicly backed McCarthy as the logical successor in an interview with Chuck Todd on MSNBC, saying, "We all think that Kevin is the right person."

McCarthy is entertaining the prospect of forcing an early leadership race and having Ryan step down before the election, The Weekly Standard reported on Sunday. On Monday afternoon, McCarthy tried to tamp down rumors of a coup, telling journalists that reports he told the White House budget director, Mick Mulvaney, about an idea to force a speaker vote this year were unfounded.

"Look, Mulvaney and I are longtime friends," McCarthy said, according to a CNN reporter. "The only thing Mulvaney has ever talked about was: 'Are you going to run for speaker if we keep the majority?'"

Another contender is House Majority Whip Steve Scalise, though he has said he would not run against McCarthy should a formal race develop.

Meanwhile, far-right groups are organizing to encourage Rep. Jim Jordan of Ohio, a longtime conservative leader in the House, to run for speaker. More than 100 leaders of conservative groups sent a letter to Jordan on Monday insisting he do so.

"We petition you to declare yourself a candidate for Speaker of the House immediately and to begin offering a platform that will inspire and engage millions of Americans," the letter says. "What is needed now — not just in this fall's congressional elections, but for years to come — is the reliable promise that the people's interest will govern, not the Swamp and its bureaucratic-industrial complex."

Ryan's power is dwindling

House Majority Leader Kevin McCarthy is the heir apparent. Win McNamee/Getty Images

At the forefront, the lower chamber's Republicans are fracturing in open displays of rebellion against Ryan.

While the ultraconservative House Freedom Caucus has always been a thorn in leadership's side, moderates are now breaking the mold and tacking their names onto a discharge petition that would force a vote on several immigration bills.

So far, 20 Republicans have signed the discharge petition. Assuming every Democrat adds their name as well, only five more Republicans would be needed to disobey Ryan and upend the floor schedule.

Ryan has been having more trouble containing dissenting voices in the conference since announcing his retirement. He failed to secure passage of the farm bill last Friday, a severe blow.

Rep. Dave Brat of Virginia, a Freedom Caucus member who often breaks with leadership, said moderates were defying Ryan because "the politics up here is broken."

"And the speaker promised the Hastert rule — 'majority of majority' — so they can't do this under regular order," Brat said. "So why is it happening? Because they're opposing their leadership, they're opposing their conference, etc."

Brat added that Ryan "cannot be forced into allowing the discharge to happen."

"All leadership has to do is put [the Goodlatte-McCaul immigration bill] on the floor, and the discharge goes bye-bye," Brat said, referring to legislation that would grant temporary protections to some young undocumented immigrants but not grant citizenship.

Scalise told reporters on Monday that the Goodlatte-McCaul immigration bill would get a floor vote during a to-be-determined day in the third week of June, right before a revote on the farm bill scheduled for June 25.

But Rep. Ryan Costello, a moderate Pennsylvania Republican retiring this year who was one of the first to sign the discharge petition, said the effort had only been emboldened in recent days.

"Going along to get along only gets you so far when they keep doing the same things, so you got to press your button, right?" Costello said.

Costello added that while he still believes Ryan should remain as speaker, the task would not be without its challenges.

"I have a great deal of respect for a lot of my colleagues that are in the Freedom Caucus," Costello said. "I've yet to see any leader corral them to do anything they don't want to do."

While the various factions in the House Republican conference are increasingly splitting apart, at the end of the day, the scheming and plotting for leadership positions might be a fruitless exercise. If Democrats manage to retake the majority, which has eluded them for eight years, the speaker's gavel could be held by a new Republican for only a few months.