Once upon a time, in the heady era of June 2015, a time when America was infatuated with Beyoncé and the New York Mets were actually good, no one thought that Donald Trump could win the presidency. He was viewed too unfavorably, those ancient people said, using a contemporary communications mechanism called "the Internet." He trailed Hillary Clinton by too much in the polls.

Nowadays, the picture is different. In a new CNN/ORC poll released on Wednesday, Trump is only six points away from Clinton -- the same margin as Gov. Scott Walker, and actually closer than Jeb Bush.

To tell this story, though, we should start by looking at each candidate's favorability, and how it has changed since CNN's last survey in July.

Since July, Hillary Clinton's favorability has dropped slightly, and her unfavorability has increased. Since July, Trump has seen an increase in how many people view him favorably, while Bush has seen a big jump in the number who view him unfavorably. (These figures are all for registered voters.) Bush is now viewed about as unfavorably as Trump on net and in raw numbers. Walker is much less-well known, and it shows in the numbers.

But notice the trend. Clinton and Bush getting less popular; Trump getting more popular.

So when we look at head-to-head match-ups, it's revealing.

Since June, all three Republicans are doing better against Clinton. She still leads them all, but by less than 10 points. In June she led all of them by double-digits.

Notice how the Republicans' fates differ. Clinton is actually doing better against Bush than in July, thanks to his having grown more unpopular. Walker grew more unpopular since July, too -- but less so than Clinton, so he improved in polling against her. And Trump's numbers improved in both his change in favorability and his match-up with Clinton. The now-sort-of-close race between them is a function of her slip and his gain in public approval.

There's some good news here for Clinton. First: She's still more popular than any of the leading Republicans and still has a better net favorability. Second, she's still beating all of them. And third, Democrats have gotten more excited about voting next year. In July, 18 percent of Democrats were "extremely" excited to vote next year. In the new poll, a full third are.

Good news for Clinton. Unless they're excited about voting for Bernie Sanders.