Representative Kevin McCarthy, the leader of the House Republicans, has lost multiple votes for Speaker due to opposition from his own party.
The Speaker of the House is an immensely powerful role that allows for near-total control over the chamber's functions.
Here's what you need to know about one of the most important jobs in American politics.
The US Constitution established the role of Speaker of the House, which oversees the lower chamber of Congress. The Speaker is both traditionally and historically a sitting member of the majority party, though this is not a constitutional requirement.
Therefore, in addition to leading the House of Representatives, they are also leader of the majority party in the chamber.
At a practical level, the Speaker sets the House's legislative agenda, controls committee assignments, sets the vote and work calendar, and is responsible for keeping their party members unified behind major initiatives.
Wielded effectively, the position of Speaker of the House is one of the most powerful in Washington. Depending on the partisan makeup of Congress, they can make or break a US president's agenda, stymie opposition, and spearhead their party's biggest legislative initiatives.
A shrewd and effective Speaker will be able to marshal their members behind their party's agenda, and control rebellious lawmakers by doling out incentives or punishments.
Former House Speaker Nancy Pelosi, a Democrat who stepped down from the position when Republicans took control of the House on 3 January 2023, was regarded as one of the most effective modern Speakers of the House.
Though the Democratic caucus she oversaw contained multiple factions, including progressives, moderates, and more conservative-leaning Democrats, she was able to use the tools available to the Speaker to keep a united front when it came to most major votes.
The House of Representatives functions on a two-year cycle, known as a "session." The new Congress began on 3 January 2023 and Republicans will be in the majority.
The very first thing a new session of the House of Representatives must do is vote for a Speaker of the House. Without that person in place, the chamber cannot move on to any other function, including swearing-in members. The chamber must continue to hold votes until a Speaker is elected.
The vote for Speaker requires a candidate to receive the support of a majority of the House - 218 votes. The existing leader of the majority party is usually presumed to be the person to assume the speakership.
For more than a century, the Speaker of the House was decided on the first vote. But that's not the case this week.
This year, Mr McCarthy, the Republican leader, seeks to become Speaker of the House now that his party is in the majority. But things haven't gone according to plan.
Over several rounds of ballots, Mr McCarthy failed repeatedly to garner 218 votes, even though his party currently holds 222 seats. A group of rebel Republicans has formed a wall of opposition, refusing to vote for Mr McCarthy in three separate rounds of ballots.
His detractors say he is beholden to special interests and not sufficiently conservative.
The stalemate has left the House of Representatives unable to move on to any other business, including swearing-in members or establishing the chamber's rules for this session. Voting will continue until the House has a Speaker, but it's unclear if Mr McCarthy will win back support. He will either have to prevail, or step aside for another candidate, or the House will not be able to function.
For the party in the minority, the head of their caucus is known simply as the "minority leader."
They do not have control over the House's functions like the Speaker does, but instead wield power within their caucus to keep lawmakers unified in opposition to the majority or advance bipartisan efforts.
In the 118th Congress, the Democrats are in the minority. Representative Hakeem Jeffries of New York was selected as the Democratic minority leader.
Watch: Kevin McCarthy's difficult Tuesday - in 90 seconds