The deals struck between the new House speaker, Kevin McCarthy, and almost 20 members of the far-right House Freedom Caucus are already emboldening the most conservative figures in the Republican party with moves set to give the caucus considerable power in the months ahead.

In order to secure the speakership McCarthy was forced into a humiliating series of defeats before his deal-making and concessions finally offered enough to bring rebel members of the Freedom Caucus onboard.

Now in McCarthy’s first days as speaker, the roughly 40-member Freedom Caucus has already scored big. Several caucus members landed plum seats on rules and appropriations panels, had a role in creating a new panel to launch a far-flung investigation of the Department of Justice (DoJ) and other agencies conservatives argue are “weaponized” against them, and stand to benefit from the gutting of House ethics oversight.

Quite a few Freedom Caucus members have close ties to Donald Trump, whose role in finally sealing the deal to give McCarthy the speakership appears to have helped notch some votes.

Craig Snyder, a former chief of staff to ex-Republican senator Arlen Specter of Pennsylvania, said the Freedom Caucus members are “bomb-throwing nihilists who try to tear down the institution without regard for consequences..

“Trump helped spur this Frankenstein monster on. It’s not a battle between extremes and the establishment, because there’s no real establishment anymore. It’s a cannibalistic brawl among extremists … It’s all about how to advance their personal brands.”

The Freedom Caucus was launched in 2015 by Ohio congressman Jim Jordan and Trump’s ex-chief of staff Mark Meadows when he was in the House. It has evolved into a more extreme version of the small government rightwing Tea Party that emerged during the Obama administration opposing Obamacare, say critics.

During Trump’s presidency, several of the Caucus’s most combative figures, including its current chairman, Pennsylvania’s Scott Perry, QAnon sympathizer Marjorie Taylor Greene and Jordan, were close allies of Trump as he sought to overturn his loss in 2020.

“They don’t do compromise very well. They take hard positions and they’re doctrinaire. The Freedom Caucus more or less became Trump’s most loyal foot soldiers,” said former congressman Charlie Dent of Pennsylvania.

Dent added: “It’s striking that individuals who humiliated the incoming speaker by withholding their votes for almost 15 rounds have been rewarded with seats on powerful committees.”

Jordan’s confrontational brand was palpable when the incoming chairman of the House judiciary committee announced a sprawling inquiry by a newly created select subcommittee he will lead into the alleged “weaponization” of the justice department, the FBI and other agencies against conservatives.

Significantly, the subcommittee is expected to have resources similar to those of the House select committee that investigated the January 6 insurrection, a chit that Freedom Caucus hardliners demanded as a reward for voting for McCarthy, whose campaign Jordan in a twist backed from the start.

The panel’s sweeping mandate, which in another concession to the holdout gives the panel power to review “ongoing criminal investigations”, immediately sparked sharp criticism from some former senior justice department officials and others.

Critics say the subcommittee’s real agenda is to provide a high-profile avenue for defending Trump from the DoJ investigation he faces into his attempted coup to stay in power and to rally the Republican base, under the guise of defending conservatives from alleged improper government targeting.

“It’s essentially an effort to stop the legitimate work of law enforcement and the justice department to secure accountability for Trump’s effort to overturn the 2020 election,” said Donald Ayer, a former deputy attorney general during the George HW Bush administration.

Michael Bromwich, a former DoJ inspector general, said: “Jim Jordan and his Freedom Caucus allies now have an institutional vehicle to air out their baseless conspiracy theories and attacks on the FBI, DoJ and the intelligence agencies. They will make a lot of noise, demonize good public servants and mislead millions of Americans.”

Similarly, Maryland congressman Jamie Raskin, a top Democrat on the House January 6 committee, told the Guardian: “This is an insurrection protection committee. These members have every interest in thwarting criminal investigations into what happened on January 6, and protecting themselves from further consequences.”

To be sure, Jordan, Perry and other key Freedom Caucus members backed Trump in several ways as he schemed about ways to block Biden from taking office by echoing some of his false charges and conspiracies about 2020 voting fraud.

Days before Christmas in 2020, Trump met at the White House with about 10 Freedom Caucus members – including Jordan, Perry, Greene, Harris, Andy Biggs and Paul Gosar – where there was talk of how his 2020 election loss could be reversed.

Perry, whose cellphone was seized last summer by federal agents and then returned, has drawn other scrutiny since he said publicly that he “obliged” Trump by introducing him in late 2020 to Jeffrey Clark, the head of the justice department’s civil division, as a useful ally at the DoJ, as Trump was prodding department leaders to support his false charges of massive voting in 2020.

Clark was referred last year to the justice department for criminal prosecution by the House’s January 6 panel, after revelations about his meetings with Trump to discuss schemes to block Biden from office including an abortive plan to elevate Clark to replace Jeffrey Rosen, who was acting attorney general, to help push baseless claims of major voting fraud in key states Trump lost.

On a related track, three caucus members, Jordan, Perry and Biggs, plus McCarthy, were all referred for ethics investigation by the January 6 panel because they stonewalled the committee’s requests and subpoenas for testimony and documents.

The trio of caucus members may well benefit from another early move by McCarthy when he pushed through a controversial change revamping the House ethics process, which effectively reduces the number of Democrats who make recommendations about reviewing members for improper conduct, a move that quickly spurred sharp criticism from Democrats and watchdog groups.

Craig Holman, a veteran ethics watchdog with the liberal group Public Citizen, said: “The emasculating of the ethics process was very self-serving for McCarthy and some members of the Freedom Caucus who were facing public investigations by OCE for refusing to comply with legal subpoenas from the January 6 committee.”

Others concur.

“The attack on the congressional ethics process is part of an effort to confer upon themselves and participants in the insurrection effective impunity and immunity,” Raskin said.

On another front that suggests growing Freedom Caucus influence, the House on a strictly party line vote passed a measure last Monday to strip $80bn from the IRS that the Biden administration helped enact last year with an eye to going after tax cheats and bolstering the famously understaffed agency by hiring 87,000 new employees.

The non-partisan Congressional Budget Office estimated that rescinding the $80bn for the IRS would increase the deficit by $114bn through 2032.

Although the House measure has little chance of passing in the Senate and Biden wouldn’t sign such a bill, it signaled how McCarthy and his allies have moved fast to go after the IRS, an agency that conservatives have long charged is biased against them.

Marc Owens, a former head of the IRS’s tax exempt organizations division, told the Guardian: “Rather than pushing for cuts to curb the agency that actually funds the government, the Freedom Caucus inspired crusade might help citizens more by pushing for adequate agency funds to go after tax cheats and sketchy non-profits, rather than protecting scammers by defunding enforcement.”

Taken together, the influence of the Freedom Caucus with McCarthy is likely to keep growing, and breed chaos.

Ex-Republican congressman Tom Davis of Virginia said the Freedom Caucus is able to “punch above its weight because there’s a slim majority … McCarthy landed the plane. But these guys [in the Freedom Caucus] were steering it.”

That outsized influence is worrisome to analysts and liberals too as battles loom over major issues like raising the debt ceiling where Freedom Caucus members seem likely to demand key spending cuts for their votes.

“The Freedom Caucus is a more extreme version of what the Republican Party used to stand for – low taxes, a small state, deregulation,” Princeton sociologist Kim L Scheppele said. “But they will take these ideas to an extreme – defunding the IRS and shutting down government.”

Raskin too noted that the Freedom Caucus’s “basic credo is they will run everything in authoritarian fashion while they’re in charge, and to make public progress impossible when they’re not running things.”

Looking ahead, Public Citizen’s Holman warned: “Expect dysfunction and chaos in Congress for the next two years. McCarthy has given away far too much of his leadership role to the Freedom Caucus, a group of rightwing Republicans whose agenda is to bring government to a halt if they do not get what they want.”