The United States House of Representatives finally has a speaker as the Republican Kevin McCarthy was elected on a historic post-midnight 15th ballot early Saturday, ending a paralyzing standoff with right-wing holdouts that raised concerns about his party's ability to exercise power in Congress.

McCarthy's victory required a historic 15 rounds of voting. It was only secured after a late-night session of high drama that saw Republican members almost come to blows as tempers flared.

It also required significant concessions to the small group of Republican conservatives who opposed his candidacy and turned a showcase of party unity into a days-long display of internal division.

The speaker wields vital influence in Washington by presiding over House business and is second in line to the presidency after the vice president.

But McCarthy has been weakened out of the gate by the protracted election and the promises he was forced to make to hardliners, who demonstrated the leverage they hold given the Republicans' wafer-thin majority in the lower House of Congress.

The chaos and confusion, watched with glee and contempt by Democrat rivals across the aisle, could signal years of legislative and decision-making paralysis on significant issues for the country – and the wider world.

Heated confrontation

As he accepted the gavel in the early hours of Saturday, McCarthy, who former president Donald Trump backed, outlined the Republicans' aggressive lines of attack ahead of the 2024 presidential race.

He vowed to "pass bills to fix the nation's challenges, from the wide open southern border to 'America last' energy policies, to woke indoctrination in our schools."

"America's long-term challenges – the debt and the rise of the Chinese Communist Party – Congress must be with one voice on both of these issues," the 57-year-old Californian told the House.

As the 14th vote got underway before midnight Friday, McCarthy suffered a shock setback amid heated exchanges as he came up short of a majority by just one vote out of more than 400 casts.

As Matt Gaetz voted "present" to deny McCarthy, the disappointed Republican leader walked to the Florida lawmaker-elect for face-to-face talks in the chamber.

In scenes shown on live television, Gaetz pointed the finger at McCarthy, who backed off before Alabama's Mike Rogers lunged at Gaetz and had to be held back with a restraining arm across his face.

"The 'Speaker' selection process, as crazy as it may seem, has made it all much bigger and more important than if done the more conventional way," Trump chimed in on his Truth Social platform.

"Congratulations to Kevin McCarthy and our GREAT Republican Party!" added the former president, who has launched his 2024 election campaign to return to the White House.

Democratic President Joe Biden optimistically called for more cooperation between the two parties.

"I am prepared to work with Republicans when I can, and voters made clear that they expect Republicans to be prepared to work with me," Biden said after McCarthy's victory.

There were more rounds of voting in the fractious 2023 contest than in any speaker election since the Civil War.

Concessions to far-right?

McCarthy had projected confidence all week, even as he was bleeding votes rather than adding to the base of around 200 Republicans who had backed him all along.

His party's takeover of Congress is also expected to herald investigations into most aspects of Biden's administration and his family.

Democrats and some of McCarthy's supporters, in private, are concerned that he has offered his far-right critics radical policy commitments that will make the House ungovernable.

There were reports that he had agreed to propose keeping spending at 2022 levels, including a cap on military funding, which would have the same effect as a $75 billion cut.

That raised the alarm among defense hawks pushing for the U.S. to project strength amid Russia's invasion of Ukraine and an emboldened Chinese stance on Taiwan.

Other lawmakers complained that McCarthy was handing the hardliners plum committee posts and changes to the rules that would severely curtail the role of the speaker.

The renegade Republicans are understood to have flipped their votes in exchange for rule changes making it possible to oust the speaker in a vote by just one member.

Democrats said the speaker role would be a poisoned chalice, as the compromises that McCarthy made would leave him the weakest speaker in modern history.