It was clear from the start that House Republicans would struggle to govern this year given their deep ideological divisions, narrow majority and myriad personal feuds and grudges. But even the most pessimistic of predictions could not have captured the remarkable, drawn-out Republican self-own now raging on Capitol Hill.

In merrily decapitating their third speaker candidate on Tuesday in a move worthy of the French Revolution, House Republicans took a situation that did not seem like it could get any worse to a breathtaking new low. They piled chaos upon chaos as members threw up their hands in frustration and anger over their inability to coalesce.

“We have no capacity at the moment to come to an agreement, and that is a very distressing place to be,” said Representative Marc Molinaro of New York, a Republican in a swing district carried by President Biden in 2020 who could potentially pay a political price for the upheaval.

By late Tuesday, Representative Mike Johnson, Republican of Louisiana, had become speaker designate No. 4, and many Republicans hoped they had finally found their man. But given the tumultuous events of the past three weeks, it was too early to predict the end was at hand, with a floor vote expected at noon on Wednesday.

Representative Tom Emmer of Minnesota, the No. 3 House Republican, lasted only about four hours on Tuesday as the party’s third speaker designate. After winning the nomination in a morning session, he was quickly brought down by conservatives questioning his right-wing credentials. Former President Donald J. Trump stuck the knife in from afar from a New York courthouse. Mr. Emmer was last seen fleeing the Longworth House Office Building with nary a word after he unceremoniously dropped out of the race.

Republicans then went back to the well in their desperate search for a speaker, with a new handful of little-known Republicans vying to become the latest to try their hand at hitting the extremely elusive magic number of 217 votes on the House floor and becoming the next speaker of the House.

Republicans were well aware they were making an international spectacle of themselves.

“I think it is apparent to the American people that the G.O.P. conference is hopelessly divided,” said Representative Steve Womack, Republican of Arkansas and one of the lawmakers who kept the speakership out of the hands of Representative Jim Jordan of Ohio last week. “Can it be overcome? Never say never. But the signs are right now that this conference is at some kind of an impasse.”

The day dawned with some hope for Republicans that they could settle the dispute and pick a speaker out of eight new contenders. There was a momentary boomlet for Mr. Emmer as he emerged victorious from an internal party nominating contest with a narrow win. But almost immediately, the far right began circling, whispering that Mr. Emmer was much too moderate for their liking as shown by his support for legal same-sex marriage and his willingness to uphold the 2020 election results in the House — evidently nonstarters for some Republicans.

After briefly staying out of the fray, Mr. Trump took aim at Mr. Emmer on social media, leveling the deadly charge that he was a RINO — Republican in name only — and unfit for the speakership. The former president, who is under indictment in four criminal cases, drove in the dagger while defending himself in a civil fraud trial in New York. That was just hours after one of his former lawyers had pleaded guilty in Georgia to a charge related to trying to fraudulently overturn the state’s presidential election results.

Mr. Emmer, the House whip, couldn’t whip up the support to overcome his detractors and he fell in short order, joining Representative Steve Scalise of Louisiana, the No. 2 House Republican, as the second elected member of the House leadership to fail to rally the troops behind him as a speaker nominee. He was actually the third, if you counted former Speaker Kevin McCarthy, ousted three weeks ago but still lingering hopefully on the sidelines should the call come for him.

“I thought Tom was well respected by everybody — until you run for speaker,” said Representative Kelly Armstrong, Republican of North Dakota. “It turns out you find out who your enemies are real quick in this job.”

House Republicans were growing increasingly irritated with their own embarrassing inability to unite around a speaker, and their Republican counterparts across the Rotunda were losing patience as well. The paralyzed House is particularly striking at a time when there is serious work to be done given the conflicts in the Middle East and Ukraine.

“They have a dysfunctional process over there, and they need to get it right,” said Senator Thom Tillis, Republican of North Carolina and himself a former speaker of the state House back home. “The next designee needs to be someone who can be elected on the floor. None of this crap we have seen over the last couple of weeks.”

Even if Republicans finally rally behind a new speaker on Wednesday or in the coming days, considerable damage has been done. Lawmakers report that they are really hearing it back home from constituents who see a bumbling mess.

“They just feel like we cannot manage,” said Representative Vern Buchanan, Republican of Florida, who called the situation “outrageous.”

Mr. Womack also despaired.

“The American public cannot be looking at this and having any reasonable confidence that this conference can be governed,” he said. “It’s sad. I’m sad. I’m heartbroken. A lot of really, really good people left in the wake here.”

Catie Edmondson and Kayla Guo contributed reporting.