Washington (CNN) Buried in the new CNN national poll is a single data point that may well be the key to how someone as unpopular as President Donald Trump can win a second term in November.

And it's this: 55% of Americans approve of the job Trump is doing on the economy, while 40% disapprove. That +15 gap is by far the best Trump performs on a series of questions on how he is handling various aspects of the country. In fact, it is one of only two measures where more Americans approve than disapprove of the job he is doing. (Trump has a +3 margin on his handling of terrorism.)

And his +15 on the economy far outstrips his overall job approval rating -- 43% approve, 53% disapprove -- in the new CNN data . (Trump's worst showings are on health care and immigration, where he is -15 and -14, respectively).

It doesn't take a political savant to see the path for Trump to a second term: the economy, the economy, the economy. The history of modern presidential elections suggests that the economy is always at the center of how voters make up their minds -- and that when people feel as though things are going well (in their personal economics and in the country) they tend to want to stay the course.

To that point: 55% of people in the CNN poll said things were going "very" or "pretty" well in the country, as compared with 43% who said they were going "pretty" or "very" badly.

Read More