What is the 25th Amendment and could it be used to remove Trump from office?

US President Donald Trump’s recent intemperate exchanges with the pope, his depiction of himself as a Christ-like figure and his threat to wipe out the civilisation of Iran have raised questions about his mental capacity to carry out his job.

This week, former CIA Director John Brennan joined calls for the 25th Amendment of the US Constitution to be invoked to remove Trump from the presidency, which he said was “written with Donald Trump in mind”.

So what is the 25th Amendment and how would it work?

What does the amendment say?

The amendment is designed to clarify some constitutional ambiguities in the event the president is unable to continue in the role. The first three sections of the amendment are straightforward and uncontroversial.

Section 1 simply states that if a vice president succeeds on the death or resignation of the president, they become president (that is, not merely acting president).

Section 2 provides the mechanism for filling a vacancy in the vice presidency.

Section 3 provides for the president to temporarily hand over the powers and duties of office to the vice president during a period of incapacity (for example, such as undergoing anaesthetic).

Section 4 is a much more complex and potentially difficult arrangement to relieve a president of the duties and responsibilities of office temporarily. The 25th Amendment tackles the problem of presidents who are unfit to continue in office, but don’t recognise their disability.

It is this section of the amendment that is currently making news because of the reaction to Trump’s recent social media posts and behaviour, and the efforts of some leading figures in Washington to invoke the 25th Amendment provision to remove Trump from the presidency.

The disability clause

Section 4 of the amendment works like this. The vice president and a majority of departmental heads declare to the speaker of the House of Representatives and the president pro tem of the Senate – the Senate’s second-highest ranking official – that the president is “unable to discharge the powers and duties of his office”. If approved, the vice president becomes acting president until such time as the president submits “a written declaration to the contrary.”

After that declaration is made, the president resumes the powers and duties of office unless the vice president and a majority of the heads of the executive departments challenge the president’s response within four days.

If that happens, Congress has 21 days to debate and decide the issue by a two-thirds vote of both houses.

It should be noted the amendment refers to “a majority of the principal officers of the executive departments” and not the Cabinet, as is often mentioned when the disability clause is reported in the media. Trump’s Cabinet consists of 21 members, only 15 of whom are principal officers of executive departments.

So, if the disability provision were to be implemented, the vice president would need eight of the department heads to join him.

The process also depends on the willingness of just one person – the vice president – to implement it, because the procedure doesn’t work with only a majority of the departmental heads.

Finally, even if the amendment was implemented, it wouldn’t actually remove Trump from the presidency. He would remain president, albeit relieved of the powers and duties of office for a temporary period. And JD Vance would only have the title of acting president.

How would it work in Trump’s case?

Even assuming the very unlikely possibility that Vance and eight of the 15 department heads would be willing to implement it, there would be a lot of uncertainty about how the 25th Amendment would work against Trump.

The major weakness of the amendment in Trump’s case would be the provision that allows the president to override the determination of the vice president and the majority of department heads by simply informing Congress that “no inability exists”.

No medical evidence is required, and the amendment doesn’t define “inability”.

Whatever his mental state may be, Trump is not physically disabled, so there would appear to be no physical impediment to him signing a piece of paper declaring that “no inability exists.”

The amendment doesn’t even require Congress to review the president’s “no inability exists” letter. Trump would be restored to the presidency the moment he transmitted the document.

For the process to be taken further, the vice president would have to move against Trump a second time, both houses of Congress would have to debate Trump’s mental state, and super-majorities in both chambers would be necessary to relieve Trump of his duties again. It would risk the 25th Amendment turning into a constitutional crisis.

All of this means any claim the 25th Amendment was “written with Donald Trump in mind” must be questioned. It may be appropriate for a president who is suffering major physical disabilities, such as Woodrow Wilson following his stroke in 1919, or James Garfield’s slow lingering death in 1881. But it is less well equipped to deal with a president who may or may not be mentally incapacitated but is physically able to fight back.

The 25th Amendment is about dealing with the temporary disability of a president not a method of impeaching the president by other means. Impeachment remains the only constitutional way of holding a president to account.