Representative Marjorie Taylor Greene of Georgia was voting on the floor of the House on the morning of June 23 when she saw her name trending on Twitter.
Ms. Greene, a high-profile, right-wing Republican who is no stranger to trending online, flicked through her feed and learned from the internet that two hours earlier, her colleagues in the ultraconservative House Freedom Caucus had voted to remove her from the group. Just then, an emissary from the caucus, Representative Ben Cline, Republican of Virginia, approached Ms. Greene. He asked if she would attend a one-on-one meeting with its chairman, Representative Scott Perry, Republican of Pennsylvania, who had been waiting to officially announce her ouster until he had spoken to her in person.
Ms. Greene balked. She couldn’t make the time, she said, because she had a meeting with Speaker Kevin McCarthy’s staff to discuss her legislation to ban transgender surgeries for children, an issue, she told Mr. Cline pointedly, “which the Freedom Caucus doesn’t care about.”
Ms. Greene and Mr. Perry never spoke.
The expulsion of Ms. Greene, perhaps the most famous hard-right rabble-rouser in Congress, from the group that has long styled itself as the rebellious voice of the extreme right in the House reflects something of an identity crisis within the Freedom Caucus even as a slim G.O.P. majority has given the group more power than ever.
As the Republican Party has moved further to the right, the fringe has become the mainstream, swelling the ranks of the Freedom Caucus but making it difficult for the group to stay aligned on policy and strategy. The rise of another hard-right faction in the House calling itself “the Twenty” — including some members of the caucus and some who have long refused to join — has raised questions in recent months about where the real power lies on the far right.
The answer could help determine the outcome of a critical period of spending battles that begin in the House this week and could culminate in a government shutdown this fall, as ultraconservative lawmakers insist on funding cuts and social policy dictates that cannot clear Congress. As the hard right expands and fractures, its members are struggling to figure out how to exert their power and divided over how disruptive they want to be.
On Tuesday, members of the group threatened to tank two spending bills that Mr. McCarthy is trying to push through the House this week before Congress leaves for its August break and show that House Republicans can move an austere spending blueprint on their own.
“We should not fear a government shutdown,” said Representative Bob Good, Republican of Virginia. “Most of what we do up here is bad anyway.”
Representative Andy Biggs, Republican of Arizona, another member of the group, said he would not support a stopgap funding bill to keep the government running in the fall. But he said the Freedom Caucus had yet to decide whether to move to block such a measure from coming to the floor.
“We’ll see how we strategize that later on,” Mr. Biggs said.
Mr. Perry, who declined to discuss the details of what led the group to remove Ms. Greene, denied that the caucus was facing a crisis, arguing that its strength lay in its shared principles, not with any one member or unanimity on every issue.
He noted that the House Freedom Caucus had played a key role in extracting concessions from Mr. McCarthy during his prolonged fight in January to be elected speaker, pushing legislation through the House to limit government spending, and forcing conservative priorities into the annual defense bill.
“One day it might be 15 members that are for something; the next day, it might be 33 members that are against something,” he said. “Sometimes your coalition changes from person to person, and that’s OK. We’re generally aligned from a holistic standpoint on what needs to be done to save the country.”
Still, Ms. Greene in some ways personifies the forces buffeting the group, which was founded in 2015 by a band of rebel conservatives who wanted to push Republican leaders to the right on fiscal and social issues.
Ms. Greene, who came to Congress as a right-wing provocateur who had embraced conspiracy theories and advocated violence against Democrats, has in recent months forged a close alliance with Mr. McCarthy, a California Republican and fixture of the G.O.P. establishment, helping him fend off a challenge to his speakership from the right and becoming an influential, if informal, policy adviser.
She also joined Mr. McCarthy in June in backing a debt limit deal with President Biden that enraged the Freedom Caucus. The bipartisan passage of the legislation illustrated the limits of the group’s power.
To Democrats, her rift with the Freedom Caucus is proof that the Republican Party has lost its mind.
“I go home and I just say, ‘Sadly the Republican conference is being held hostage by the extreme of their party,’” said Representative Andrea Salinas, a first-term Democrat from Oregon. “I say, ‘They’re so extreme that they kicked out Marjorie Taylor Greene.’ The rooms just erupt. People are like, ‘What?’”
To Republicans, the dispute merely reflects the evolution of a group that has grown as the party has changed. When the Freedom Caucus was founded, it was a tight-knit group whose complicated bylaws required members to reach consensus on every position. It stood for “open, accountable and limited government, the Constitution and the rule of law, and policies that promote the liberty, safety and prosperity of all Americans,” according to its mission statement.
The caucus sprang to life several months before Donald J. Trump announced his presidential candidacy in June 2015, and presaged his populist complaint of a Republican Party more beholden to Washington special interests than to the average taxpayer.
Although top officials including Mr. McCarthy, who then served as House majority leader, decided against stripping members of their committee assignments, they worked to marginalize the Freedom Caucus, which made clear that it was willing to use guerrilla tactics on its own party in service of its goals.
“There were always forms of intimidation, from threatening to strip you of your committee assignment to not inviting you on political trips to meet donors,” recalled former Representative Raúl R. Labrador, a founder of the group who now serves as Idaho’s attorney general. “The message was, if you don’t kiss the ring, you’re not going to have any of the benefits of membership. And we told them to go pound sand.”
During the Trump presidency, the group of rebels rose to wield immense power in Washington, a point of pride for the caucus. Two of its founding members, former Representatives Mick Mulvaney of South Carolina and Mark Meadows of North Carolina, went on to serve as White House chiefs of staff.
These days, the group is larger and harder to organize, in part because its members are, by nature, not rule followers. Some complain that when the group takes an official position, they do so on a messaging app, Telegram, and don’t take votes in person. Mr. Perry has at times vented privately that he has little control over his own caucus. And Republicans aligned with the group have grumbled behind closed doors that the quality of the members has diminished over time.
The group includes populist G.O.P. members like Representative Eli Crane of Arizona, who says he was sent to Washington simply to disrupt the status quo, alongside more traditional libertarian conservatives like Representative Josh Brecheen of Oklahoma, who believes in limited government and spending cuts. There are members like Representative Chip Roy of Texas, who is backing Gov. Ron DeSantis of Florida for president and has been at odds with Mr. Trump since he declined to vote to overturn the 2020 election results. And there are Trump loyalists like Representative Byron Donalds of Florida, whom allies have been floating as a potential Trump running mate.
One of the unifying principles of the group these days may be a shared hatred of Mr. McCarthy. And yet one of the most prominent members of the Freedom Caucus and a founder of the group, Representative Jim Jordan, Republican of Ohio, now serves as the chairman of the powerful Judiciary Committee and has been brought into the fold by the speaker.
At the same time, some of the most vocal hard-right voices in the House who have sought to thwart Mr. McCarthy’s rise and his agenda, like Representative Matt Gaetz, Republican of Florida, have never been members.
Mr. Gaetz, however, has emerged as a charter member of the Twenty, a group of 20 populist members that has in recent months become the more disruptive threat to Mr. McCarthy’s control of the House. The smaller group views itself as a more efficient fighting force. It does not take votes to establish official positions; its members just go out and disrupt, as they did in June when they staged a blockade on the House floor to protest Mr. McCarthy’s debt limit deal with President Biden.
“The base is looking for fighters and some sort of evidence that we’re fighting,” Representative Jeff Duncan, Republican of South Carolina, said. “I get that.”
On Capitol Hill, where the personal is political, individual policy differences and strategic disputes can quickly mushroom into full-blown fights.
Ms. Greene’s disillusion with the group dates back to the last Congress, when Democrats, then in the majority, stripped her of her committee assignments and fellow Freedom Caucus members told her that Mr. McCarthy had helped engineer her removal. It was not until a year later that she learned that Mr. McCarthy had strenuously objected to her ejection, and she began warming up to him.
Freedom Caucus members including Mr. Perry, Representatives Andrew Clyde of Georgia, Bob Good of Virginia and Ralph Norman of South Carolina were livid about her coziness with Mr. McCarthy, as they viewed the whole point of their group as needling and thwarting party leaders until they got their way. The situation became so awkward that Ms. Greene stopped attending the group’s regular Monday night meetings at the Conservative Partnership Institute a few blocks from the Capitol.
Her status as persona non grata in the group was further cemented during the debt ceiling fight, when she again stood by Mr. McCarthy’s side and vouched for a bipartisan fiscal deal that Freedom Caucus members railed against as a broken promise that would not significantly reduce federal budget deficits.
Ms. Greene also had policy frustrations with the group. She complained that the Freedom Caucus refused to support her legislation that would place a federal ban on transgender surgeries for children under the age of 18. Mr. Roy, the group’s policy chairman, and Mr. Perry both argued that such matters should be up to the states.
The divides were already bitter by the time Ms. Greene and Representative Lauren Boebert, who have long disliked each other personally, got into a yelling match on the House floor last month. Ms. Greene was caught on video berating her colleague in vulgar terms for introducing an article of impeachment against President Biden that Ms. Greene claimed had been her idea.
The incident prompted an emergency breakfast meeting the following morning, in which the group voted overwhelmingly to kick out Ms. Greene. Mr. Jordan was one of the few members who voted to keep her.
Mr. Jordan and Ms. Greene have been the Freedom Caucus’s top two fund-raisers, raising questions about whether the group’s members — including Ms. Boebert, a Colorado Republican who relied heavily on support from the caucus last year to eke out an unexpectedly narrow 546-vote victory over her Democratic challenger — would suffer from having cut loose the high-profile Georgia Republican.
Mr. Perry said he was not worried.
“I will tell you,” he said breezily, “the Freedom Caucus is doing just fine.”