The House of Representatives plans to vote Tuesday on a resolution that would formally request that Vice President Mike Pence invoke the 25th Amendment to remove President Donald Trump from office. The debate is scheduled to begin at 4:30pm ET, with the vote expected between 7:30 p.m. ET and 10:30 p.m. ET. If it passes, Pence would have 24 hours to respond, House Speaker Nancy Pelosi has said, before the House begins the impeachment process on Wednesday.

House Democrats were blocked Monday in their attempt to fast-track the resolution. House Republicans are expected to have divided opinions about backing the request.

The move follows last week’s attack on the US Capitol building by hundreds of Trump supporters, which Trump is widely believed to have incited in a speech immediately preceding the insurrection. The riot resulted in five deaths and at least 120 arrests for, among other things, the destruction of federal property. Social networks banned Trump’s accounts, cabinet members and staffers resigned and businesses have cut ties or dropped their support. Trump called the actions a “witch hunt” on Tuesday and defended his speech as “totally appropriate.”

If the 25th Amendment is successfully invoked by a unanimous Congressional vote (read more about the process below), Pence would immediately serve as acting president until the Jan. 20 inauguration of President-elect Joe Biden. Use of the 14th Amendment has also become a source of conversation in legal circles.

Read more: Could Trump pardon himself before leaving office? What to know

What is Pence’s stance on invoking the 25th Amendment, and how is that amendment different from impeachment? What could happen if the 25th Amendment isn’t invoked? How has Trump been affected by the 25th Amendment before? We explain below, including where the situation stands now.

Who backs using the 25th Amendment right now?

So far, nearly 240 Washington lawmakers — 38 Democratic senators and 199 representatives from both parties have called for Trump’s removal. Pelosi, in a letter to colleagues, called Trump “an imminent threat” to democracy and the US Constitution after he repeated lies about the November election he lost and urged supporters at a Wednesday rally to march to the Capitol as it began the process of certifying Biden’s Electoral College win and told them to “fight much harder” and “show strength.” 

“The president’s speech was riddled with violent imagery and calls to fight harder than before,” noted the New York Times in its analysis of Trump’s remarks. “By contrast, he made only a passing suggestion that the protest should be nonviolent, saying, ‘I know that everyone here will soon be marching over to the Capitol building to peacefully and patriotically make your voices heard.'”

During Trump’s impeachment last year, one of his defenses was that the primary accusation against him — that he abused his presidential power by withholding aid to Ukraine in an attempt to get its president to announce a corruption investigation into Biden — wasn’t an ordinary crime, so it did not matter even if it were true. Most legal specialists said that made no difference for impeachment purposes, but in any case, that argument would not be a defense here. Several laws clearly make it a crime to incite a riot or otherwise try to get another person to engage in a violent crime against property or people.

Will Pence invoke the 25th Amendment? What we know today

Pence has not made a public statement about his position on using the 25th Amendment to remove Trump from office. However, on Tuesday, the New York Times reported that Pence and Trump spoke for more than an hour about the riot and Trump’s remainder of the term, suggesting that Pence will not act. 

Pence has reportedly been on the fence. On Sunday, CNN reported that the vice president had “not ruled out” invoking the 25th Amendment, wanting to leave the option open in case Trump becomes unstable, CNN reported, citing a source close to the vice president. According to the source, Pence has been concerned about Trump’s potential behavior if the 25th Amendment or impeachment should occur, potentially leading to actions that may endanger the nation. 

What is the 25th Amendment to the US Constitution?

The 25th Amendment pertains to the president’s ability to perform the duties of office and what happens in the event that the commander in chief can no longer do their job. It empowers the vice president to temporarily assume the powers of the presidency, enabling a smooth transition of power in an emergency.

The amendment also enables the president to nominate a vice president if there’s a vacancy. 

Read more: FBI posts on Twitter, Facebook seeking help IDing people involved in Capitol Hill violence

The part of the 25th Amendment under discussion generally relates to Section 4, which allows the vice president and a majority of the president’s cabinet or a group designated by Congress to declare, in writing to the Senate president pro tempore and House speaker, that the sitting president is unable to perform the duties of the office. This immediately makes the vice president the acting president. 

The president can resist this effort by the vice president and Congress, however, declaring him or herself fit for office in official writing. From there, the vice president and those supporting impeachment have four days to disagree, or the sitting president resumes the presidency. If they disagree, Congress can settle the matter with a vote. 

What might happen if the 25th Amendment isn’t invoked?

The 25th Amendment requires the vice president and Cabinet members to support and initiate the invocation. With at least two Cabinet members having resigned, Education Secretary Betsy DeVos and Transportation Security Elaine Chao, and Pence up to this point rebuffing demands to begin 25th Amendment proceedings, House Democrats are preparing to start the potentially lengthy process to impeach Trump for the second time in his four-year term. Here are the details we know, including how likely impeachment is to come to a vote and what the outcome could mean for Trump even after Biden is sworn in as the 46th president of the United States.

In addition, there’s been talk about using the 14th Amendment — specifically Section 3 — to remove Trump from office. In simple terms, Section 3 says that if a person has engaged in an “insurrection or rebellion” against the US, they cannot hold office. Read the full section below. But constitutional law experts say that this option is unlikely, as the 14th Amendment has never been used to oust a sitting president before. 

Section 3 of the 14th Amendment says: 

No person shall be a Senator or Representative in Congress, or elector of President and Vice President, or hold any office, civil or military, under the United States, or under any State, who, having previously taken an oath, as a member of Congress, or as an officer of the United States, or as a member of any State legislature, or as an executive or judicial officer of any State, to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same, or given aid or comfort to the enemies thereof. But Congress may by a vote of two-thirds of each House, remove such disability.

What Trump said that could invoke the 25th Amendment

Before chaos erupted on Capitol Hill on Jan. 6, Trump had told supporters at a rally nearby that “we will never give up, we will never concede.” Trump’s tweets, some of which were deleted or blocked by Twitter, continued to spur the crowd. 

“We’re going to walk down Pennsylvania Avenue … and we’re going to the Capitol,” Trump, 74, said at the rally. Afterward, supporters marched to the Capitol, where violent rioters broke past barricades, smashed windows and doors, attacked Capitol police and unlawfully entered the building, prompting members of the Senate and House to be sequestered to ensure their safety. Hours passed as constituents and lawmakers urged Trump to call for the mob to stand down. 

Officials in the Trump administration said that Pence, and not Trump, had approved an order to deploy the Washington, DC National Guard. This authority is traditionally reserved for the president. 

Trump eventually gave a brief taped statement on Wednesday telling the rioters to go home, calling them “special people,” adding, “We love you,” even as he continued to circulate false claims of voter fraud. 

As night fell, social media cracked down on Trump, with Twitter and Facebook flagging and deleting multiple posts, as well as placing temporary locks on the president’s accounts.

On the morning of Jan. 7, Trump committed to an “orderly” transition of power, and on Thursday night, condemned the riots he had a direct hand in inciting. On Jan. 8, Twitter permanently banned Trump’s account “due to the risk of further incitement of violence” and said reports are already circulating that rioters may storm the Capitol again on Jan. 17 — days ahead of Biden’s Jan. 20 inauguration.

What would it take to for the 25th Amendment to take effect?

The invocation of the 25th Amendment is considered extraordinary and the use of the amendment’s Section 4 is unprecedented: A variety of conditions must come together for the vice president to assume the duties of the president this way.

For Section 4 of the 25th Amendment to take effect, the vice president would need to secure the support of a majority of the cabinet chiefs and then alert congressional leaders. Alternatively, Congress can designate another body instead of the cabinet. Following the vice president’s notification of congressional leaders, the president can request the return of his presidential powers. 

If the 25th Amendment is invoked, Pence, 61, would assume Trump’s presidential responsibilities. Trump could then declare to the House speaker and the president pro tempore of the Senate that there is “no inability” for him to govern. At that point, it would be up to Congress to decide on the matter within 21 days, which would pass the Jan. 20 date when Biden takes office. That essentially means Pence would serve briefly as our 46th president and then pass on the presidential powers to Biden, who won the November election with 81.28 million votes, or 51.3 percent of the votes cast.

Congress isn’t in session and would need to be called back, if it came to that. Every sitting senator would have to unanimously agree. 

Congress considered using the 25th Amendment against Trump before

The 25th Amendment has been discussed before during Trump’s presidency. On Oct. 1, Trump announced on Twitter that he and first lady Melania Trump had tested positive for COVID-19.

Following his coronavirus diagnosis and hospitalization, Pelosi introduced legislation that would allow Congress to enact the 25th Amendment if the president became incapacitated, although she insisted at the time that the legislation wasn’t specifically aimed at Trump.

When released from Walter Reed National Military Medical Center, Trump, while still under physician supervision and being treated with the steroid dexamethasone, abruptly stopped stimulus check negotiations, only to reinstate them hours later, and offered a stimulus package that ultimately fizzled out. Congressional Democrats discussed invoking the 25th Amendment, but didn’t bring the matter to a vote.

Has the 25th Amendment ever been used on a president before?

Section 4, the portion largely referenced in recent days, has never been enacted, only coming close once during an attempted assassination of President Ronald Reagan in 1981. 

Congress approved the 25th Amendment in 1965. It was ratified and certified as an amendment the following year by President Lyndon Johnson. 

The first use of the other sections of the 25th Amendment came in 1973 when President Richard Nixon nominated Gerald Ford to replace Vice President Spiro Agnew, who had resigned. The amendment was used once more when Nixon resigned and Ford assumed the presidency and chose Nelson Rockefeller to fill the vice presidency. 

Most recently, President George W. Bush twice invoked the 25th Amendment to temporarily transfer the powers of the presidency to Vice President Dick Cheney while Bush underwent colonoscopies under anesthesia, first in 2002 and again in 2007. In 1985, his father, then-Vice President George H. W. Bush, received 25th Amendment authority from President Ronald Reagan.