President Trump was “unglued” when he ordered steel and aluminum tariffs, a White House official told NBC News. (Olivier Douliery/Bloomberg)

A word that one would probably rather not see in reference to the guy who can launch nuclear missiles at the push of a button is “unglued.” Yet, in a report from NBC News about President Trump’s sudden and angry decision to announce new tariffs on steel and aluminum, that’s the word used. It’s not NBC’s words; reporters Stephanie Ruhle and Peter Alexander spoke with a White House official who used it to describe Trump’s fury on Wednesday evening, angry at his staff and his attorney general. So the president “became ‘unglued’.”

Americans probably aren’t surprised.

What many voters liked about Trump as a candidate is that he said whatever he wanted to. (This was often described as his “saying what he thinks,” which is a different and less accurate descriptor.) He was “not PC,” meaning that he was more than willing to kick off his campaign by giving a freestyle speech about how Mexican immigrants are mostly criminals, we never beat Japan at anything, and how his opponents didn’t know how to work air conditioning, so how could they beat the Islamic State?

Trump prided himself not only on saying things that others might find ill-advised, but on espousing a foreign and campaign policy predicated on being erratic. He refused to say what he planned to do in the future both because it maintained flexibility and obviated the need for him to later change his plans.

It didn’t take long for his detractors to point out that these traits were atypical for a president and to suggest that they were perhaps not optimal for someone in that position. That, perhaps, he lacked the temperament and stability needed to serve as president.

Polling before the election showed that Americans generally agreed. Only a third of voters said that Trump had the personality and temperament it takes to serve effectively as president in Post-ABC polling during 2015 and 2016.

Republicans believed that he had the right temperament — particularly once Trump secured their party’s nomination. But even then, fewer than three-quarters of Republicans said those terms applied to Trump.

After the election, Quinnipiac University regularly asked Americans if Trump was “levelheaded” — a different question, certainly. Only about 3-in-10 Americans use that word to describe Trump, including about two-thirds of Republicans most of the time. The number among Republicans shot up in late January; we’ll see if that lasts.

In January, Trump tried to put to rest any questions about his emotional stability by, well, saying that he was stable.

Pollsters naturally rushed to ask Americans if they agreed. Both Quinnipiac, and The Post and ABC News asked Americans to evaluate Trump’s stability. In both polls, fewer than half of Americans said that “stable” accurately described the president of the United States. That included 84 percent of Republicans in our poll, though only half of Republicans said Trump was a genius.

So you’ll forgive the electorate if their reaction to hearing that Trump came “unglued” and acted rashly is a lack of surprise. America said before the election that it questioned Trump’s temperament and has said ever since that it doesn’t think Trump is levelheaded.

Of course Trump would lose his temper. It’s Trump.