What is the 25th Amendment? Here’s what you need to know

After a chaotic day Wednesday with pro-Trump rioters breaching barricades and breaking windows amid violent clashes between the mob and police inside the U.S. Capitol, some lawmakers are calling for President Donald Trump to be removed from office using an amendment from the U.S. Constitution.

The 25th Amendment is the constitutional provision that deals with the transfer of presidential power, either temporarily or permanently.

On Wednesday, David Cicilline, the Congressman for Rhode Island’s 1st District, sent a letter along with California Rep. Ted Lieu and more than a dozen other colleagues on the House Judiciary Committee, calling on Vice President Mike Pence to invoke the 25th Amendment to remove Donald Trump from office after Wednesday’s events.

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"For the sake of our democracy, we emphatically urge you to invoke the 25th Amendment and begin the process of removing President Trump from power," Cicilline wrote in the letter to Vice President Pence. "President Trump has shown time and time again that he is unwilling to protect our democracy and carry out the duties of the office."

Both chambers of Congress abruptly recessed Wednesday afternoon as they were debating the count of the Electoral College votes that gave Joe Biden the presidency.

Arizona was the first of several states facing objections from Republicans as Congress took an alphabetical reading of the election results. Rep. Paul Gosar of Arizona rose to object to the typically routine acceptance of electors.

Meanwhile, Trump spoke at a rally Wednesday morning near the White House, where several thousand protestors cheered the president and his disproven claims of widespread election fraud.

"We will not let them silence your voices," Trump told the protesters. "We will stop the steal." After the charged rally, a crowd of Trump’s supporters made their way to the U.S. Capitol, breaking down barricades, scaling walls and breaking windows to breach the Capitol building.

RELATED: 1 shot dead after pro-Trump mob storms Capitol, breaking windows and violently clashing with police

The pro-Trump rioters violently clashed with police and camped out in lawmakers’ offices, with some even being photographed taking things from the building. A woman was shot dead amid the chaos inside the Capitol.

Lawmakers on both sides of the aisle criticized Trump for fanning the flames by repeating false claims of widespread voter fraud and relentlessly questioning the integrity of the 2020 election, with some calling for the president to be impeached for a second time, and others calling for use of the 25th Amendment.

But the most recent instance of the 25th Amendment being discussed in relation to Trump wasn’t the first.

In October, House Speaker Nancy Pelosi said that Democrats planned to discuss the 25th Amendment after President Donald Trump contracted COVID-19, just weeks before the Nov. 3 election.

In an October press conference, Pelosi said the president needed to disclose more about his health after his diagnosis — including when he first contracted the virus as others in the White House became infected.

After Trump’s COVID-19 diagnosis, Pelosi chose not to invoke the 25th Amendment, which details how presidential power can be transferred in the event a president is unable to do the job.

What is the 25th Amendment and how does it work?

The amendment was added to the U.S. Constitution following the assassination of President John F. Kennedy in 1963.

President Lyndon B. Johnson in his 1965 State of the Union promised to "propose laws to insure the necessary continuity of leadership should the President become disabled or die." The amendment was passed by Congress that year and ultimately ratified in 1967.

To temporarily transfer power to the vice president, a president sends a letter to the Speaker of the House of Representatives and President pro tempore of the Senate that they are "unable to discharge the powers and duties of his office."

RELATED: ‘Un-American’: Republican, Democrat lawmakers condemn Trump supporters who breached Capitol

The vice president then becomes acting president. When the president is ready to resume authority, the president sends another letter — which is spelled out in the amendment’s Section 3.

Section 4 of the amendment lays out what happens if the president becomes unable to carry out their duties but doesn’t transfer power. In that case, the vice president and majority of the Cabinet can declare the president unfit. They would then send a letter to the Speaker and President Pro Tempore saying so. The vice president then becomes acting president.

If the president ultimately becomes ready to resume their duties, the president can send a letter saying so. But if the vice president and majority of the Cabinet disagree, they can send a letter to Congress within four days. Congress would then have to vote. The president resumes their duties unless both houses of Congress by a two-thirds vote say he or she is not ready. That section has never been invoked.

Has it ever been invoked?

Presidents have temporarily relinquished power — but not all invoked the 25th Amendment. Previous transfers of power have generally been brief and happened when the president was undergoing a medical procedure.

In 2002, President George W. Bush became the first to use the amendment’s Section 3 to temporarily transfer power, to Vice President Dick Cheney while Bush was anesthetized for a colonoscopy. Bush temporarily transferred power in 2007 to undergo another colonoscopy.

When President Ronald Reagan was shot in 1981, his administration prepared — but did not sign — the letters necessary to invoke the 25th Amendment, according to the Reagan Library and Museum.

But Reagan did temporarily transfer power to Vice President George H. W. Bush while undergoing surgery to remove a polyp from his colon in 1985, but he said at the time he wasn’t formally invoking the 25th Amendment.

While he said he was "mindful" of it, he didn’t believe "that the drafters of this Amendment intended its application to situations such as the instant one." Bush was acting president for eight hours according to a book on the amendment by John D. Feerick.

The Associated Press contributed to this story. This story was reported from Los Angeles.