The president was acting strangely. In the wake of a scandal about his illegal dealings with foreign powers, White House aides felt he was so “inattentive and inept” that a memo sent to the chief of staff raised the prospect of invoking the 25th Amendment to remove him from office.

The president was Ronald Reagan, who was dealing with fallout from the Iran-Contra scandal. His chief of staff ultimately dismissed the possibility of using the 25th Amendment to remove him, but the incident is one of the few cases in American history in which White House staff seriously suggested it as an option for removing a president from office, based on his ability to perform the job.

Howard H. Baker Jr. was just starting his job as Reagan’s chief of staff in 1987 when he asked two aides to investigate how the Iran-Contra scandal was affecting the White House. James Cannon, the aide who wrote the memo about the investigation, reported back that the place was in chaos.

The staff “told stories about how inattentive and inept the president was,” Cannon recalled to journalists Jane Mayer and Doyle McManus in Landslide: The Unmaking of the President, 1984-1988. “He was lazy; he wasn't interested in the job. They said he wouldn't read the papers they gave him—even short position papers and documents. They said he wouldn't come over to work—all he wanted to do was to watch movies and television at the residence.”

At the time, Reagan was the oldest president the country had ever had. “President Reagan was an older man in his 70s, and he showed it,” writes Stephen F. Knott, a professor of national security affairs at the United States Naval War College, in an email. He “was never a detail person; fell asleep at cabinet meetings in the midst of briefings from droning bureaucrats; was horrible at remembering names… This was a man who required lots of rest and recreation.”

Cannon suggested that Baker consider whether the fourth section of the 25th Amendment could apply to this situation. That section gives the vice president and the cabinet the ability to remove the president if he is “unable to discharge the powers and duties of his office.”

Baker took Cannon’s memo seriously and observed the president afterwards. But because he personally didn’t observe the behavior detailed in the memo, he dismissed the idea of using the amendment.

Ever since Reagan revealed he’d developed Alzheimer’s in 1994, people have speculated about whether the disease began during his presidency and caused these behaviors. Doctors who treated him have disputed this, as does Knott, who is also a previous co-chair of the presidential oral history program at the University of Virginia’s Miller Center of Public Affairs.

“I'll just say right off the bat that I'm not of the school of thought that believes Reagan was suffering from ‘mental health issues,’” Knott writes. Looking at his final years as president, “I don't see mental illness, nor do I see Alzheimer's.” But that’s not to say Reagan didn’t have other health issues as well.

Reagan had developed hearing problems as a young actor in the 1930s when someone fired a gun too close to his right ear on set. He had multiple surgeries to remove polyps and precancerous growth. And just a couple months into his presidency, he nearly died from a gunshot wound.

Knott says that when John Hinckley, Jr. tried to assassinate Reagan in 1981, the president “came closer to dying than we were led to believe at the time.” In fact, Knott actually believes this was an instance in which officials should have invoked the 25th Amendment, but didn’t “out of fear of upsetting the public, the markets, along with allies and adversaries.”