The Republicans' leading House of Representatives speaker candidate has failed on 11 attempts to win enough votes to secure the integral role in an event not seen in more than 160 years.
Despite offering concessions in a bid to woo 20 hardline Republicans who have refused to throw their support behind him, the party's House leader Kevin McCarthy on Thursday (local time) again failed to garner enough votes to win the speaker's gavel.
It's not the longest time the House has gone without a speaker. In 1855, it took 133 rounds of voting over two months for the chamber to finally elect Nathaniel Prentice Banks of Massachusetts to the role.
But it has now reached a level of dysfunction not seen since 1859 - 164 years - when it took 10 votes to select a leader in the turbulent run-up to the Civil War.
The failure to elect a speaker has paralysed the US House of Representatives. Source: AAP / Sipa USA
With its inability to choose a leader, the 435-seat House has been rendered impotent - unable even to formally swear in newly elected members let alone hold hearings, consider legislation or scrutinise Democratic President Joe Biden and his administration.
Why is Kevin McCarthy's path to the speaker's chair so difficult?
Republicans won a slim 222-212 House majority in the November midterm elections, meaning Mr McCarthy cannot afford to lose the support of more than four Republicans, as Democrats united around their own candidate, Hakeem Jeffries.
Mr McCarthy, a congressman from California who was backed by former President Donald Trump for the post, offered a range of concessions that would weaken the speaker's role, which political allies warned would make the job even harder if he got it.
At least 200 Republicans have backed Mr McCarthy in each of the . Fewer than 10 per cent of Republican politicians have voted against him but they are enough to deny him the 218 votes needed to succeed Democrat Nancy Pelosi as speaker.
Twenty Republicans have continued to vote for other candidates over three days.
Democratic speaker nominee Hakeem Jeffries (right), and former US House Speaker Nancy Pelosi. Source: AAP, AP / Alex Brandon
He also offered the ability for any single member to call a vote that could potentially remove him from the post - a step that helped drive at least one prior Republican speaker, John Boehner, into retirement.
Those concessions could potentially help Mr McCarthy win over some of the holdouts but would leave him more vulnerable to the hardliners through the rest of the next two years if he ultimately wins the speakership.
But despite this, they remain unyielding, saying that they do not trust Mr McCarthy to stick to the scorched-earth tactics they want to use against Mr Biden and the Democratic-controlled Senate.
"This ends in one of two ways: either Kevin McCarthy withdraws from the race or we construct a straitjacket that he is unwilling to evade," said Republican Representative Matt Gaetz, who voted for Mr Trump for speaker.
What could happen next?
Mr McCarthy's supporters say they are making progress in closed-door talks, but none have predicted a resolution any time soon.
"I can tell you there's some good things happening," said Representative Marjorie Taylor Greene, a McCarthy supporter who is among the most outspoken conservatives in the House. "I think we're going to see some movement."
But if Mr McCarthy ultimately fails to unite Republicans, they would have to search for an alternative.
Possibilities include number two House Republican Steve Scalise and Representative Jim Jordan, who have both backed Mr McCarthy.
Mr Jordan received 20 votes when nominated by the holdouts on Tuesday.
