Washington (CNN) House Majority Leader Kevin McCarthy dropped out of the race to succeed Speaker John Boehner on Thursday, a shocking move that throws the House into chaos.

Boehner, R-Ohio, holds a copy of the Constitution on Capitol Hill in Washington on May 7, 1992, as Sen. Don Nickles, D-Oklahoma, looks on. Both men proclaimed it was a historic day when the Michigan House ratified the 27th Amendment to the Constitution, which would require that any Congressional pay raises not go into effect until after the next election.

Boehner, R-Ohio, holds a copy of the Constitution on Capitol Hill in Washington on May 7, 1992, as Sen. Don Nickles, D-Oklahoma, looks on. Both men proclaimed it was a historic day when the Michigan House ratified the 27th Amendment to the Constitution, which would require that any Congressional pay raises not go into effect until after the next election.

Boehner at a Capitol Hill news conference on February 6, 1995. He has had a seat in the U.S. House of Representatives since 1990. Before that he was a member of the Ohio State House of Representatives for six years.

Boehner at a Capitol Hill news conference on February 6, 1995. He has had a seat in the U.S. House of Representatives since 1990. Before that he was a member of the Ohio State House of Representatives for six years.

Boehner dumps out coal, which he called a Christmas gift to President Clinton, during a news conference about the federal budget on December 21, 1995. Many government services and agencies were closed at the end of 1995 and beginning of 1996 as a Republican-led Congress battled Clinton over spending levels.

Boehner dumps out coal, which he called a Christmas gift to President Clinton, during a news conference about the federal budget on December 21, 1995. Many government services and agencies were closed at the end of 1995 and beginning of 1996 as a Republican-led Congress battled Clinton over spending levels.

President George W. Bush signs into law the federal education bill No Child Left Behind at a high school in Hamilton, Ohio, in 2002. The law offered the promise of improved schools for the nation's poor and minority children and better-prepared students in a competitive world. Boehner, second from right, backed the bill.

President George W. Bush signs into law the federal education bill No Child Left Behind at a high school in Hamilton, Ohio, in 2002. The law offered the promise of improved schools for the nation's poor and minority children and better-prepared students in a competitive world. Boehner, second from right, backed the bill.

Boehner, center, and fellow Republican House members sing Boehner's birthday song during a news conference on Capitol Hill on November 17, 2006. Boehner served as the House Minority Leader from 2007 to 2011.

Boehner, center, and fellow Republican House members sing Boehner's birthday song during a news conference on Capitol Hill on November 17, 2006. Boehner served as the House Minority Leader from 2007 to 2011.

Boehner, center, looks on as President Barack Obama speaks with then-House Majority Leader Steny Hoyer in the East Room of the White House on February 23, 2009. Boehner and Obama have butted heads over the years.

Boehner, center, looks on as President Barack Obama speaks with then-House Majority Leader Steny Hoyer in the East Room of the White House on February 23, 2009. Boehner and Obama have butted heads over the years.

Boehner, an avid golfer, talks with Tiger Woods while golfing at the Congressional Country Club in Bethesda, Maryland, in 2009.

Boehner, an avid golfer, talks with Tiger Woods while golfing at the Congressional Country Club in Bethesda, Maryland, in 2009.

Boehner voices his concerns about the health care reform bill championed by Obama during a news conference in Washington on October 29, 2009.

Boehner voices his concerns about the health care reform bill championed by Obama during a news conference in Washington on October 29, 2009.

Boehner hugs his wife, Debbie, after addressing the crowd at the NRCC Election Night watch party on November 2, 2010, when Republicans took back control of the House of Representatives. Boehner met his wife in college, and they have been married since 1973.

Boehner hugs his wife, Debbie, after addressing the crowd at the NRCC Election Night watch party on November 2, 2010, when Republicans took back control of the House of Representatives. Boehner met his wife in college, and they have been married since 1973.

On January 5, 2011, Boehner wipes away tears as he waits to receive the gavel from outgoing House Speaker Nancy Pelosi, D-California, during the first session of the 112th Congress.

On January 5, 2011, Boehner wipes away tears as he waits to receive the gavel from outgoing House Speaker Nancy Pelosi, D-California, during the first session of the 112th Congress.

Boehner presents golfing legend Arnold Palmer with the Congressional Gold Medal at a special ceremony in the Rotunda of the Capitol in September 2012.

Boehner presents golfing legend Arnold Palmer with the Congressional Gold Medal at a special ceremony in the Rotunda of the Capitol in September 2012.

Boehner is sworn in as the speaker of the House after his re-election in January 2013.

Boehner is sworn in as the speaker of the House after his re-election in January 2013.

Boehner speaks to the media after a meeting with President Obama at the White House in October 2013, the second day of the federal government's recent shutdown. The White House squared off with Republican rivals in Congress over how to fund federal agencies, many of which were forced to close, leaving a fragile economy at risk.

Boehner speaks to the media after a meeting with President Obama at the White House in October 2013, the second day of the federal government's recent shutdown. The White House squared off with Republican rivals in Congress over how to fund federal agencies, many of which were forced to close, leaving a fragile economy at risk.

Reporters question Boehner as he arrives at the U.S. Capitol as the government stalemate continued in October 2013. President Obama signed a bill on October 17 that ended the 16-day shutdown and raised the debt ceiling.

Reporters question Boehner as he arrives at the U.S. Capitol as the government stalemate continued in October 2013. President Obama signed a bill on October 17 that ended the 16-day shutdown and raised the debt ceiling.

Boehner blasts conservative groups during a press conference in December 2013 after passing a compromise budget deal aimed at removing the threat of another government shutdown. Fed up with criticism from conservative advocates, Boehner said they were "misleading their followers." He followed up with: "Frankly, I just think that they've lost all credibility."

Boehner blasts conservative groups during a press conference in December 2013 after passing a compromise budget deal aimed at removing the threat of another government shutdown. Fed up with criticism from conservative advocates, Boehner said they were "misleading their followers." He followed up with: "Frankly, I just think that they've lost all credibility."

The image of the Speaker of the House John Boehner (R-OH) is displayed in a monitor of a camera as he talks with reporters in his office in the Capitol in November 2014 in Washington.

The image of the Speaker of the House John Boehner (R-OH) is displayed in a monitor of a camera as he talks with reporters in his office in the Capitol in November 2014 in Washington.

U.S. Vice President Joe Biden and Speaker of the House John Boehner await the arrival of President Barack Obama for the State of The Union address on January 20 in the House Chamber of the Capitol.

U.S. Vice President Joe Biden and Speaker of the House John Boehner await the arrival of President Barack Obama for the State of The Union address on January 20 in the House Chamber of the Capitol.

U.S. President Barack Obama walks with Speaker of the House John Boehner as they depart the annual Friend's of Ireland luncheon on Capitol Hill in Washington on March 17.

U.S. President Barack Obama walks with Speaker of the House John Boehner as they depart the annual Friend's of Ireland luncheon on Capitol Hill in Washington on March 17.

Afghanistan President Ashraf Ghani (right) expresses his country's gratitude for America's fiscal commitment and military sacrifices during an address to a joint meeting of the United States Congress with Vice President Joe Biden (left) and Speaker of the House John Boehner (R-OH) in the House Chamber of the U.S. Capitol March 25 in Washington.

Afghanistan President Ashraf Ghani (right) expresses his country's gratitude for America's fiscal commitment and military sacrifices during an address to a joint meeting of the United States Congress with Vice President Joe Biden (left) and Speaker of the House John Boehner (R-OH) in the House Chamber of the U.S. Capitol March 25 in Washington.

Pope Francis walks with Speaker Boehner and Vice President Joe Biden after delivering a speech to Congress in Washington on September 24.

Pope Francis walks with Speaker Boehner and Vice President Joe Biden after delivering a speech to Congress in Washington on September 24.

John Boehner has been the speaker of the U.S. House of Representatives since 2011, making him second in line for the presidency, behind the vice president. On September 25, Boehner told colleagues he's stepping down as speaker and will leave Congress at the end of October. Look back at his career in politics so far.

John Boehner has been the speaker of the U.S. House of Representatives since 2011, making him second in line for the presidency, behind the vice president. On September 25, Boehner told colleagues he's stepping down as speaker and will leave Congress at the end of October. Look back at his career in politics so far.

The move came without warning as House Republicans were in a closed-door meeting to select their nominee for speaker, with McCarthy's wife and kids in the room. Boehner subsequently postponed the vote.

"I think I shocked some of you, huh?" McCarthy told reporters following the decision.

"If we're going to unite and be strong, we need a new face to do that," McCarthy said, adding that he did not want to win the race on the House floor with only enough votes to squeak by.

A source close to McCarthy told CNN the decision to drop out came down to "numbers, pure and simple," adding that "he had the votes to win the conference vote, but there just wasn't a path to 218" -- the number of votes needed to lock down the speakership on the House floor.

The uncertain future of House GOP leadership comes less than a month before Congress must take action to raise the debt ceiling to keep the U.S. from defaulting on its debt obligations -- a critical vote conservatives have in the past sought to stall in order to pull concessions from Democrats.

Senate Minority Leader Harry Reid was quick to call on Republicans to "bring a clean debt ceiling increase to the floors of the House and Senate immediately" to avoid a credit downgrade. "Republican chaos is likely to get worse before it gets better but the economic livelihood of the American people should not be threatened as a result of Republicans' inability to govern," Reid said in a statement.

McCarthy's candidacy ran into trouble last week after he suggested that the House's committee on Benghazi was an attempt to hurt Hillary Clinton's poll numbers.

Asked if that affected his decision, McCarthy acknowledged: "Well, that wasn't helpful."

Rep. Dana Rohrabacher, R-California, described McCarthy's move as "courageous," saying this is "exciting" for the party because there is now a "wide open" race for speaker.

"Because of his verbal blunder last week there were some of us that were very apprehensive and this going to create great unity among Republicans," Rohrabacher said.

Meanwhile, not one to miss an opportunity, GOP presidential candidate Donald Trump suggested he was partly responsible for McCarthy's failed bid, days after he suggested McCarthy wasn't tough enough for the job.

"They're giving me a lot of credit for that because I said you really need someone very, very, tough and very smart. Ya know smart goes with tough, I know tough people that aren't smart that's the worst. We need smart, we need tough, we need the whole package," Trump said at a campaign stop Thursday in Las Vegas.

Who's next?

The announcement immediately set off a round of speculation about who could win the job. Perennial candidates floated included Wisconsin Rep. Paul Ryan and South Carolina Rep. Trey Gowdy — both of whom ruled it out explicitly. Several House Republicans said Georgia Rep. Lynn Westmoreland was considering it, and others suggested Oregon Rep. Greg Walden, the chairman of the National Republican Congressional Committee.

"I would consider it," Walden said when asked by CNN about members floating his name for speaker. But he said he's not actively campaigning and noted that some are pushing the idea of an interim speaker. Several candidates have suggested a senior or retiring member should serve as speaker for the next 14 months and pledge to not run again. Rohrabacher suggested Texas Rep. Joe Barton or Kentucky Rep. Hal Rogers.

Boehner said in a statement he will remain in his post until a new speaker is elected, though he has yet to announce the date for the new vote.

Photos: The hand-off: How Speakers Ryan to O'Neill came to power Photos: The hand-off: How Speakers Ryan to O'Neill came to power The current Speaker of the U.S. House of Representatives is Paul Ryan, a Republican from Wisconsin. He gained his power from his predecessor, former Speaker John Boehner, after the Ohio Republican shocked the political world by deciding to vacate his position. Click through for other recent speakers: Hide Caption 1 of 8 Photos: The hand-off: How Speakers Ryan to O'Neill came to power Former Speaker John Boehner, a Republican from Ohio, gained his power from his predecessor, former Speaker Nancy Pelosi, when the GOP gained the majority of seats in the House in the 2010 midterm elections. Boehner announced his intention to leave the position in September 2015, and Paul Ryan succeeded him in October. Hide Caption 2 of 8 Photos: The hand-off: How Speakers Ryan to O'Neill came to power U.S. Rep. Nancy Pelosi was the first and only female speaker of the House. Her speakership lasted from January 4, 2007, to January 3, 2011. Pelosi, a Democrat, lost her seat to the Republican majority in the 2010 midterms. John Boehner took the gavel. Hide Caption 3 of 8 Photos: The hand-off: How Speakers Ryan to O'Neill came to power Dennis Hastert remains the longest serving Republican speaker in history, from January 6, 1999, to January 3, 2007. However, the GOP lost its majority in the House of Representatives, leaving Democrat Nancy Pelosi to become speaker. On Thursday, May 28, Hastert was accused in an indictment of lying to the FBI and evading currency reporting requirements as he sought to pay off a subject to "cover up past misconduct." On Thursday, October 28, Hastert pleaded guilty in the case. Hide Caption 4 of 8 Photos: The hand-off: How Speakers Ryan to O'Neill came to power Newt Gingrich broke the four-decade line of Democratic speakers by becoming speaker from 1995 to 1999 and was named Man of the Year by Time magazine for the accomplishment. He then fell from grace after a disappointing 1998 midterm election for the GOP, prompting him to step down from both the speakership and Congress. Gingrich's resignations came as a complete surprise to many, as the speaker had been fighting to keep his top job until the announcement. Hide Caption 5 of 8 Photos: The hand-off: How Speakers Ryan to O'Neill came to power Tom Foley, a Democrat who represented Washington state in the House for 30 years, took over the office of the speaker after the resignation of Jim Wright. Foley served as speaker from 1989 to January 1995 but was defeated in the 1994 election by George Nethercutt. Hide Caption 6 of 8 Photos: The hand-off: How Speakers Ryan to O'Neill came to power Jim Wright of Texas served two years as speaker, after Massachusetts Democrat Tip O'Neill retired. But he stepped down in 1989 after facing a House Ethics Committee investigation on improprieties with the sale of his book and fees from speaking engagements. He was the first speaker to resign in the face of a scandal. He died on May 6, 2015, at 92. Hide Caption 7 of 8 Photos: The hand-off: How Speakers Ryan to O'Neill came to power A Massachusetts Democrat who served as speaker from 1977 until retirement in 1987, Tip O'Neill was well-known for his deal-making as well as his collegiality with former President Ronald Reagan. Former Speaker Nancy Pelosi thought to commemorate the 34-year congressional career of O'Neill with an office building on the edge of Capitol Hill that bears his name. O'Neill was the longest continuously serving House speaker of any party in U.S. history. Hide Caption 8 of 8

"I'm confident we will elect a new speaker in the coming weeks. Our conference will work together to ensure we have the strongest team possible as we continue to focus on the American people's priorities," he said in a written statement.

Boehner also canceled a scheduled appearance Thursday night on "The Tonight Show with Jimmy Fallon," an NBC spokeswoman said.

Republican Study Committee Chairman Bill Flores twice dodged reporters' questions about whether he would rule out his own run, but also spoke against the idea of a caretaker.

"An interim will not give us the opportunity to cast that big bold vision that we need. Interims are caretakers, caretakers tend to do safe things," Flores said. "The electorate put us here in November of 2014 to take big steps, and we need to find the leader that will help us take those big steps. ... The other thing that happens with interim is you have people trying to run for the permanent position, and so you have all the distractions we've gone through the last two weeks. We don't need that."

Rep. Jason Chaffetz, who late last week jumped into the speaker's race, called an impromptu news conference less than an hour after Republicans began pouring out of the GOP conference meeting. The Utah Republican said he was also "absolutely stunned, surprised and shocked."

Chaffetz said he would continue to campaign for the top House post and said "we need to find somebody that our whole body can unite behind and do what were elected to do."

"I do believe it is time for a fresh start. That was the whole genesis for my campaign, but we need to have a lot more family discussion," he said. "I think we have a lot of internal fracturing that's happening. And we need to figure out a way to unite the party."

Westmoreland joked said he is thinking about it, joking that, "I'd like to talk to my wife first."

Asked why he thought he could get 218 votes he said, "I don't know that I can, but all I can say is I'm willing to try."

Ryan, the chairman of the Ways and Means Committee and someone who had been viewed as a contender for the job, immediately said he is not interested.

"While I am grateful for the encouragement I've received, I will not be a candidate. I continue to believe I can best serve the country and this conference as Chairman of the Ways and Means Committee," Ryan said in a statement.

With conservatives again floating his name, Gowdy said he will not run for speaker. Asked if he would reconsider and join the race if his GOP colleagues urged him to get in, he replied, "No."

Immediate reaction

Rep. Tim Huelskamp, a Kansas Republican and member of the conservative House Freedom Caucus that opposed McCarthy's bid, said the decision creates a "brand new race for speaker."

"I am not the one," McCarthy told the stunned Republicans in the meeting, according to Huelskamp.

Huelskamp also took shots at McCarthy, saying the majority leader was campaigning for the top post until "three hours ago" and said the lack of "advance notice" was characteristic of the "stunts" that have defined Boehner's leadership as speaker -- including his surprise resignation the day after Pope Francis addressed a joint meeting of Congress.

And just as McCarthy got a brief heads up moments before that announcement, McCarthy also gave Boehner notice shortly before Thursday's conference meeting, a Boehner aide told CNN.

Members had no indication the move was coming. "Totally stunned," Rep. Peter King, R-New York, said on CNN.

Westmoreland met with McCarthy in his office this afternoon and said he didn't expect him to endorse anyone.

"What Kevin has done is extremely selfless, and I think he's done a brave and courageous thing," said Rep. Louie Gohmert, R-Texas. "He was close to being right there and he chose to unite the conference rather than waging battles. "

Reminder of late 1990s chaos

Speaking on CNN, Rep. Walter Jones said the current unrest reminds him of the late 1990s. Newt Gingrich stepped down as speaker and Rep. Bob Livingston was selected to take over but quickly removed himself from consideration after it was revealed he had an extramarital affair.

Jones wrote an open letter Tuesday stating any leadership candidate should quit their campaigns "if there are any misdeeds he has committed since joining Congress that will embarrass himself, the Republican Conference, and the House of Representatives if they become public."

Jones told CNN that he was looking out for the institution and not pointing fingers at anyone in particular.

"I think when a person has been a member of the Congress — which is a very sacred duty, quite frankly, in my opinion — and they are elevated to become a leader of a party -- could be either party, Republican or Democrat -- that those in leadership must be above reproach," Jones said.

"And all I was doing, not trying to single anybody out, but was to say in this makeup of office — the majority office and the speakers office -- all the members should be made to say I have nothing in my background that could be of embarrassment to the Republican conference, the House of Representatives or the American people," he added. "That's all this was about."