Donald Trump. AP At The New York Times, Nate Cohn points out a puzzle in the polling about President Donald Trump.

Trump's approval figures look disastrous — easily the lowest of any incoming president during the era of modern opinion polling. (And before you say polling is worthless, remember: The final national polls were only a point or two off from the final result.)

Yet if you examine measures other than approval and favorability, Trump's polling looks considerably less dire.

Cohn summarizes a recent Quinnipiac poll:

"Just 37 percent of registered voters — a narrower group than the adult population — view him favorably or approve of his performance. But just about every other question is better for Mr. Trump: 45 percent think he'll take the nation in the right direction, and 52 percent of registered voters are optimistic about the next four years with Mr. Trump as president."

Cohn isn't entirely sure what to make of this gap, though he raises the possibility that Trump stands to benefit from more public support than his simple approval numbers suggest.

The way I think about these polls is that they identify the most important piece of the electorate, a group I like to call the "Trump-curious."

You don't have to like Trump to think he might do a good job

These polls show that a surprisingly large group of people — perhaps 15% of registered American voters — disapprove of Trump but are open to the idea that he will be a good president.

This isn't the largest slice of the electorate. Both Trump superfans and Trump loathers are larger groups than the Trump-curious.

But the median voter is Trump-curious. The next presidential election — and the midterm election to come in 2018, as well the actions of legislators who are driven by perceptions of whether Trump and his agenda are popular — will be determined by how Trump-curious voters feel Trump is doing.

This past election was also decided by the Trump-curious: Trump won overwhelmingly among the substantial number of voters who viewed both him and Hillary Clinton negatively.

Therefore, it behooves both Trump and his opponents to court these voters assiduously.

Getting inside the heads of the Trump-curious

I hear a lot of commentary from liberals about Trump's relationship to the public that verges on "LOL nothing matters." Trump can lie about anything, this thinking goes, talk about how awesome he is, and his fans will eat it up and view him as a great success.

This is probably true of some people — but not of enough people for Trump to command broad popular support or get reelected.

Remember, Trump-curious voters tell pollsters that they have an unfavorable view of Trump and disapprove of the way he has handled the presidential transition. They're not enamored of Trump. They're not drinking his Kool-Aid.

They're not necessarily prepared to believe Trump had the largest inaugural crowds ever just because Sean Spicer, the White House press secretary, says he did. But they probably also don't care that much that Sean Spicer is a liar — they might not even know who Sean Spicer is.

What motivates someone to vote for Trump even if they dislike him? Well, one common possibility last year was a deep and abiding dislike for Clinton.

But people who tell pollsters that they are hopeful about Trump's presidency, and that they think he will be good at managing various things including the economy, must see some upsides in him.

Maybe they hope he will create jobs and cause wages to rise. Maybe they think he can restore manufacturing employment and revitalize communities that feel as if they are in decline. Maybe they think he can knock some heads together and get increasingly ideological members of Congress to work together.

If you're a liberal who supported Bill Clinton, you can probably relate to the idea that someone might support a politician with bad personal qualities, including a tendency toward inappropriate sexual behavior in the workplace, if they thought that politician was delivering the right outcomes.

But soon, the question of whether Trump can deliver as president will not be theoretical.

Trump will lose the Trump-curious if he is seen as ineffectual

If the Trump-curious come to see Trump as failing to deliver on his campaign promises, he will not be able to fall back on a reservoir of personal goodwill, since these voters already dislike him personally.

Trump has a tendency to make promises on a grand scale. We're going to bring the jobs back, he says, and take care of everyone on healthcare. Obamacare will be replaced with something far better and cheaper. We'll build a wall and Mexico will pay for it. "American carnage" stops today.

Trump's challenge is to come as close as possible to delivering on these promises. It's going to be hard.

Hillary Clinton's often unsatisfactory policy messaging was shaped in part by a recognition that a lot of the things people are unhappy about — high healthcare costs, the decline of manufacturing employment — are driven by economic forces over which the president has limited leverage. This will remain true with Trump as president.

Trump's opponents' challenge will be to point out where Trump is failing to meet his promises.

Roughly, this means engaging in what Luigi Zingales, a professor at the University of Chicago's business school, calls normal politics. Zingales, based on his experience watching Silvio Berlusconi in Italy, advises that if your opponent is a total weirdo who is temperamentally and morally unsuited to lead a country, you still beat him by pointing out that he is not doing his job well and you can do it better.

Of course, it is also fine to point out that Trump is a total weirdo who is temperamentally and morally unsuited to lead a country. This widely held observation is a key reason his poll ratings are so poor, and repeating it is important for mobilizing his strong opponents.

But anti-Trumpers must acknowledge that some voters are so dissatisfied with establishment politicians that they have chosen to take a flyer on a man they realize is an unsuited weirdo because they hope he might fix problems nobody else seems to be able to.

To win these Trump-curious voters over, Democrats must show that he is a failure — not that he is weird and bad.

Ideally, they should also offer their own compelling alternative vision.