Rep. Matt Gaetz is threatening to oust Speaker Kevin McCarthy. It won't be easy.

One of House Speaker Kevin McCarthy's harshest critics plans to make good on his threat to remove the California Republican from his leadership post

“How would you be different as speaker, compared to Mr. Boehner?” a reporter asked then-House Majority Leader Kevin McCarthy in September 2015 as the California Republican pursued, and eventually gave up, his first attempt at the speakership.

McCarthy laughed while standing next to outgoing Speaker John Boehner — who had just stepped down after facing a threat of removal — and joked that he was from a different generation and wouldn't be as tan.

Eight years later, McCarthy is finding that there are fewer differences between them as he faces a conservative revolt against his speakership.

"If somebody wants to remove (me) because I want to be the adult in the room, go ahead and try,” McCarthy told reporters Saturday.

And his critics, namely Rep. Matt Gaetz, plan to do just that. On Sunday, the far-right Republican from Florida threatened to use a procedural tool — called a motion to vacate — to try and strip McCarthy of his office as soon as this week after he relied on Democrats to provide the necessary votes to fund the government.

"I think we need to rip off the Band-Aid,” Gaetz said on CNN. “I think we need to move on with new leadership that can be trustworthy.”

Here’s what you need to know about how the House can remove a speaker:

WHAT IS A MOTION TO VACATE?

The rules of the House allow for any single lawmaker — Democrat or Republican — to make a “motion to vacate the chair,” essentially an attempt to oust the speaker from that leadership post through a privileged resolution.

It's a rare and strong procedural tool that has only been used twice in the past century. But in recent years, conservatives have wielded the motion as a weapon against their leaders.

In January, McCarthy, hoping to appease some on the hard right as he fought to gain their vote for speaker, agreed to give as few as five Republican members the ability to initiate a vote to remove him. But when that wasn’t good enough for his critics, he agreed to reduce that threshold to one — the system that historically has been the norm.

Proponents of allowing a single lawmaker to file the motion said it promotes accountability, noting its long history in the House. The last use of the motion was in 2015, when then-Rep. Mark Meadows of North Carolina, a Republican who later became Donald Trump’s White House chief of staff, introduced a resolution to declare the speaker’s office vacant. Two months later, Boehner said he would be stepping down.

No speaker has ever been removed from office through a motion to vacate.

HOW DOES IT WORK?

At any point in time, a member of the House can introduce a privileged resolution —a designation that gives it priority over other measures — to declare the office of the speaker of the House of Representatives vacant.

Once the motion is introduced, the lawmaker can walk onto the House floor and request a vote. Such a request would force House leaders to schedule a vote on the resolution within two legislative days.

But there are procedural motions that members of either party could introduce to slow down or stop the process altogether. If those tactics were to fail, and the resolution came to the floor for a vote, it would take a simple majority of the House — 218 votes, when no seats are vacant — to remove the speaker.

While it has never been successful, a motion to vacate has been used as a political threat against several speakers throughout history, dating back to Republican Speaker Joseph Cannon — who first invoked the resolution against himself in 1910. The effort failed as his fellow Republicans voted overwhelmingly to keep him as their leader. But by calling the bluff of his detractors, Cannon was able to put them on the record and end the threats against him.

In 1997, Republicans frustrated with then-Speaker Newt Gingrich considered trying to oust him but eventually decided against it. Most recently, the mere whispers of a motion to vacate forced Boehner out of office and set McCarthy on the path to the leadership post he has today.

WHO IS TRYING TO OUST MCCARTHY AND WHY?

Just like for Boehner, the call for McCarthy’s removal began with just one man. Gaetz, a member of the ultra-conservative House Freedom Caucus, has been threatening to file the resolution to remove him from the dais ever since McCarthy was nominated speaker by a majority of the conference earlier this year.

Gaetz is among 20 or so members who voted against McCarthy round after round as he fought to become speaker. While others eventually relented and voted in favor of McCarthy or present, Gaetz fought until the very end.

“This will all be torpedoed by one person who wants to put a motion to vacate for personal, political reasons, and undermine the will of the conference and the American people, who elected a Republican majority to govern,” Rep. Mike Lawler, R-N.Y., a defender of McCarthy, said Sunday on ABC.

Gaetz and other critics of McCarthy say he has failed to be the conservative leader the party needs. They have railed against his deal with the White House over raising the debt limit earlier this year and have demanded the House slash spending levels to new lows. The group has also made sweeping demands to reimagine the U.S. government, which they criticize as “woke and weaponized.”

DOES A MOTION TO VACATE HAVE THE VOTES TO PASS?

As of right now, it is unclear, but there's reason to be skeptical. No matter how loud or disruptive they may be, the anti-McCarthy faction is only a small minority in a Republican conference that is mostly supportive or amenable to him remaining speaker.

Another problem with the push to remove McCarthy is that there is no clear, consensus candidate to take his place. And lastly, and maybe more importantly, Gaetz would need the support of most Democrats to oust McCarthy if the motion ever came to a vote — and it's far from certain that they would join him.

“The one thing I agree with my Democrat colleagues on is that for the last eight months, this House has been poorly led and we own that and we have to do something about it,” Gaetz said on the floor last week. “And you know what? My Democrat colleagues will have an opportunity to do something about that, too. And we will see if they bail out our failed speaker.”

Gaetz has been speaking to House Democrats from across the ideological spectrum in recent weeks trying to assess what kind of support, if any, he would have from those across the aisle if he were to file his motion and it came to the floor.

“We haven’t had a discussion about any hypothetical motion to vacate,” Democratic Leader Hakeem Jeffries said at a news conference Saturday. “We’ll cross that bridge when we get to it.”

IF THEY OUSTED MCCARTHY, WHAT WOULD HAPPEN NEXT?

The House would enter uncharted territory if a motion to vacate effort against McCarthy were to pass the full House.

The speaker of the House, under the rules of the chamber, is required to keep a list of individuals who can act as speaker pro tempore in the event a chair is vacated. The list, which is oddly written by the sitting speaker at any given time, remains with the House Clerk and would be made public if the speakership were vacant.

The first person on that list would be named speaker pro tempore and their first order of business would be to hold an election for a new speaker. That event requires the House to vote as many times as it takes for a candidate to receive the majority of those present and voting for speaker.

For McCarthy, that process took an unprecedented 15 rounds in January.

New candidates for speaker could emerge, but there's also nothing to stop Republicans from nominating McCarthy again.