The presidential seal is affixed to a podium before U.S. President Donald Trump, not pictured, speaks during an event at the Local 18 Richfield Facility of the Operating Engineers Apprentice and Training center in Richfield, Ohio, U.S., on Thursday, March 29, 2018. Both Congress and Trump’s own infrastructure advisers have shied away from the kind of sweeping infrastructure plans Trump discussed at a February White House meeting with local and state officials. (Bloomberg)

Quick: How could a sitting U.S. president be legally removed from office? Most people have heard of impeachment, a power granted to (and rarely used by) the U.S. Congress. But there’s also the 25th amendment to the U.S. Constitution, which provides an avenue for a president to be removed under extraordinary circumstances by his or her own leadership team. Critics of President Donald Trump have cited the amendment approvingly, even wishfully, over the past two years while reviewing what they consider his erratic behavior. Now an unnamed senior official in the Trump administration says the amendment was discussed within Trump’s own presidential cabinet.

1. What does the 25th amendment say?

It provides that a president can be removed if the vice president and a majority of the cabinet determines he or she is “unable to discharge the powers and duties” of the office. If the president contests the finding, and the vice president and cabinet persist, Congress can order the president’s removal by a two-thirds vote in both chambers. The amendment also clarifies that the vice president is the successor if a president leaves office in midterm, and that the vice president becomes acting president when, say, a president undergoes major surgery.

2. Why does this even exist?

To address some questions about presidential and vice presidential succession that the Constitution didn’t specifically answer. For instance, when President William Harrison died in office in 1841, there was a debate over whether Vice President John Tyler would become acting president, or president, or officially remain vice president. (Tyler decided on his own to have a judge administer the presidential oath of office.) The 25th amendment was introduced in Congress, and ratified by the requisite three-quarters of U.S. states, after the 1963 assassination of President John F. Kennedy. In the immediate confusion following the shooting of Kennedy, there were tense questions about who would run the country should he survive but only in a semiconscious or otherwise grievously wounded condition.

3. Has the amendment been used before?

Never to remove a sitting president, but twice to fill a vacant vice presidency. (Before the amendment took effect, the U.S. occasionally went long periods without any vice president.) In 1973, after Spiro Agnew was forced to resign because of tax-evasion charges, President Richard Nixon nominated Representative Gerald Ford to become vice president. He was approved by the House and Senate. After Nixon resigned the following year, Ford became president and nominated Nelson Rockefeller, a former governor of New York, as vice president. He was confirmed by Congress.

4. Why is the amendment coming up now?

In an op-ed column published Sept. 5 by the New York Times, a person identified only as “a senior official in the Trump administration” said “many Trump appointees have vowed to do what we can to preserve our democratic institutions while thwarting Mr. Trump’s more misguided impulses until he is out of office.” The op-ed author wrote, “Given the instability many witnessed, there were early whispers within the cabinet of invoking the 25th amendment, which would start a complex process for removing the president. But no one wanted to precipitate a constitutional crisis. So we will do what we can to steer the administration in the right direction until -- one way or another -- it’s over.”

To contact the reporters on this story: Laurence Arnold in Washington at larnold4@bloomberg.net;Anne Cronin in New York at acronin14@bloomberg.net

To contact the editors responsible for this story: Leah Harrison Singer at lharrison@bloomberg.net, Larry Liebert, Lisa Beyer

©2018 Bloomberg L.P.