A question that has been on the tip of many, if not most, Americans' tongues the better part of two years — “Is Donald Trump fit for the office of the presidency?” — is spilling into the open in the mainstream media.

We all need to be very, very careful.

It’s time to talk about Trump’s mental health,” blared a headline from Washington Post columnist Eugene Robinson this week.

“I really question his ability to be — his fitness to be — in this office,” former director of national intelligence James R. Clapper Jr. said Tuesday night after Trump's rambling speech in Arizona.

“He’s unhinged. It’s embarrassing,” CNN's Don Lemon declared Tuesday night, adding, “There was no sanity there.”

Sen. Jack Reed (D-R.I.) said on a hot mic a month ago: “I think he’s crazy. I mean, I don’t say that lightly and as a kind of a goofy guy.” Sen. Susan Collins (R-Maine) responded, “I'm worried.”

Longtime Hillary Clinton aide Philippe Reines went there a couple of weeks back:

CNN's Brian Stelter noted Sunday that journalists have often wondered about these questions privately and off-camera: “Is the president of the United States a racist? Is he suffering from some kind of illness? Is he fit for office? And if he’s unfit, then what?”

Even a Republican senator seemed to allude to the president's fitness last week. Sen. Bob Corker (R-Tenn.) said Trump “has not yet been able to demonstrate the stability nor some of the competence” to be president.

Corker, of course, didn't directly suggest that Trump has mental problems — and perhaps that wasn't even his intention. Clapper also didn't directly say it, but it's difficult not to attach fitness for office to one's faculties. In fact, I'm not sure what else Clapper could have even meant by his comments.

Here's what we can say about this:

  1. It's completely true that this is something lots and lots of Americans are concerned and/or wondering about, making it a valid topic.
  2. It's a completely pertinent issue, given that we are talking about the president of the United States here.
  3. It's verging on impossible to cover in a responsible way.

So how many people actually question Trump's fitness? The most direct poll question on this topic comes from an automated SurveyUSA poll in February. It found that 30 percent of Americans labeled Trump's mental health as “poor.” Thirteen percent labeled it “just fair,” and 49 percent labeled it “good” or “excellent.” A slight majority of Democrats (51 percent) picked “poor.”

But there's another long-standing poll question that I think gets at this in a less direct but telling way — on Trump's “temperament.” Pollsters have long asked about this and found that as many as two-thirds of Americans think Trump doesn't have the right temperament to be president. That's not exactly saying he's mentally unfit, but it does suggest they don't quite trust him to be a stable leader making well-reasoned decisions. So even if only 30 percent label Trump's mental health “poor,” it's clear that plenty of people worry, as Corker did, about his stability — whether mental or otherwise.

As for Point No. 2, it's self-evident that the American people have an overwhelming interest in knowing whether their president is fit for office. And Trump has only helped to legitimize this topic by virtue of his completely unprecedented conduct in the Oval Office. He almost seems to crave this type of speculation.

But Point No. 3 is the sticking point. The problem with this topic is that there is almost nothing to go on except speculation. The American Psychiatric Association has on multiple occasions warned its members against talking about Trump's mental state, and it reiterated that long-standing policy to me Wednesday.

“Our position on the Goldwater Rule hasn’t changed — it’s still unethical for a member of the APA to offer a professional opinion on the mental state of someone they have not evaluated,” spokeswoman Amanda Davis said.

The American Psychological Association agrees. “The American Psychological Association’s Code of Ethics counsels psychologists against diagnosing living individuals whom they have not personally assessed,” spokeswoman Kim Mills said.

So if professionals aren't supposed to go there, how in the world can amateurs without mental-health expertise offer informed opinions about this topic? It's just asking for trouble.

There are certainly other ways to talk about this, though. One is to point to the shoddy medical reports that Trump has turned in from his zany doctor, Harold Bornstein. As I've noted, Bornstein's reports seem to have deliberately omitted medications that Trump is taking, including the hair-loss drug Propecia. The manner in which these reports have been handled provides very little confidence that we have a sober, well-considered evaluation of Trump's health — mental or physical — on record.

And some in Congress are pushing for more on that. Fully 15 percent of House Democrats (29 of them) have signed off on a bill to create an Oversight Commission on Presidential Capacity to verify a president's mental and physical fitness for the job. This is likely to go nowhere in the GOP-controlled House, of course.

From there, the onus is really on political actors — like Clapper and, potentially, even Republicans like Corker — to raise this as an issue and say they want answers, if, in fact, they are that concerned. As a topic for cable news panels and think pieces, this risks devolving into armchair psychiatrists and Trump critics saying things they're not qualified to weigh in on.

Stelter noted Sunday: “These are upsetting, polarizing questions; they're uncomfortable to ask. But we in the national news media can't pretend like our readers and viewers aren't already asking. They are asking: Is the president of the United States suffering from some sort of illness? Is he racist? Is he fit to be commander in chief?”

It's 100 percent true that these are real questions that lots of people have. But we also have to deal with the facts as we know them, and getting to any kind of demonstrable truth on this topic is extremely difficult, with a huge amount of peril along the way. Even raising the topic implies a judgment about Trump's faculties.

From there, it's up to high-ranking officials to do something if they see fit. And agitating for that is about the only course for those who think this is a real issue.

The American Psychological Association put it this way: “The question of whether the president is able to discharge the powers and duties of the office is the stated responsibility of the vice president and other key federal officials, as specified by the 25th Amendment to the Constitution. Therefore, we would look to our federal officials to carry out their constitutional responsibilities related to the presidency.”