One of the interesting and unanswered questions about the 2016 campaign is this: How is it possible that the race seems close, even though large majorities of Americans consistently tell pollsters that they don’t think Donald Trump is qualified or temperamentally fit for the presidency?

This week’s Post poll, for instance, found that 62 percent of Americans say they don’t think Trump “is qualified to serve as president,” while only 36 percent say he is qualified. By contrast, they say by 60-39 that Hillary Clinton is qualified. Meanwhile, they also say by 61-30 that Clinton has the “better personality and temperament to effectively serve as president.” Previous Post polls have shown similar findings.

Meanwhile, a CNN poll from July found that 67 percent said Trump does not have “the right experience to be president,” while 64 percent said that Clinton does have the right experience.

Is there any precedent in the modern polling era for a major party nominee to be regarded as unqualified for the job or fundamentally unfit for it by such large majorities?

Hillary Clinton leads Donald Trump by 5 points among likely voters, according to a new Washington Post/ABC News poll. (Bastien Inzaurralde/The Washington Post; photos: Melina Mara/Post; Jabin Botsford/Post)

There actually might not be any precedent for it. But it’s hard to answer this question definitively, because polling on these questions has been very sporadic. Pollsters tend to poll on topics that are the focus of public concern or public debate, and this has not often been a big question in elections, so it has not been polled on frequently. In a way, that underscores the point: In this election, the question of whether Trump is fundamentally qualified has been a much more pressing one than it has in many previous elections.

The data we do have on this, however, is instructive. At my request, the crack Post polling team dug through the archives of the Roper Center for Public Opinion Research, and came up with these historical examples:

* In February of 2012, a Pew poll found that American voters said by 48-42 that Mitt Romney was “well-qualified to be president.”

* In late October of 2008, a Pew poll found that 56 percent of voters said Barack Obama, then a first-term Senator, was “well-qualified to be president.”

* In October of 2008, an NBC News/Wall Street Journal poll found that 55 percent said Sarah Palin is “not qualified to be president.”

* In October of 2008, a Newsweek poll found that 55 percent said Palin is not “qualified to step in as president.”

* In July of 1992, a Time/CNN poll found that 65 percent said Dan Quayle was not “qualified to be president if something were to happen” to President George H.W. Bush.

* In March of 1992, a Los Angeles Times poll found that 51 percent said Bill Clinton was “qualified to be president.”

* In July of 1992, a Time/CNN poll found that 60 percent said Al Gore was “qualified to be president if something were to happen to Bill Clinton.”

And so, Trump fares worse than even Sarah Palin did on perceptions of the level of qualification for the presidency. The only figure who had worse rankings on this than Trump was poor Dan Quayle. Trump also fares worse than did Obama, a first term Senator, or Bill Clinton, the governor of Arkansas. (Yes, this is an imperfect comparison because it involves comparing different pollsters. Also, if anyone digs up any more polling on this, I’ll add it.)

Now, its hard to say whether this will end up mattering at all. It’s possible, as Nate Cohn has speculated, that if Trump ends up being viewed as unqualified or unfit by a substantial enough percentage of Republican voters, Hillary Clinton could end up winning by a large margin. (As it happens, this week’s Post poll crosstabs tell us that a surprisingly high 23 percent of Republicans say Trump is not qualified.)

But it’s also possible, as Emily Guskin and Scott Clement have argued, that the effect of this could end up being blunted. That’s because some of the Republican or GOP-leaning independent voters who say Trump is not qualified might also think Clinton is equally unqualified, or perhaps even more so, and thus vote the party line, because they nonetheless find keeping Clinton out of the White House an overriding goal. (Party loyalty and negative partisanship are also obviously factors.)

Still, one thing we do know is that the vast gap in perceptions here — large majorities view Clinton as qualified and fit for the job, while comparably large majorities view Trump as unqualified and unfit for it — continues to be neglected in commentary about how historically disliked the two candidates are. There may not be any precedent in recent decades for a major party nominee to be seen as unqualified by such large majorities. That may not end up mattering in the end. But it seems like another important data point in assessing how unusual, or even abnormal, the Trump candidacy really is.