Barack Obama’s job approval rating is down to 45 percent in the lastest CNN/ORC poll, conducted June 11-13, with 54 percent disapproval. The approval number is down from 53 percent in CNN/ORC’s May 17-18 poll. Most interesting result: Obama is getting only 48-percent approval from those age 18 to 34, only 3 percent above his national average.

By way of comparison, Obama’s 66 percent of the vote among 18-29s in November 2008 was 13 percent above his 53-percent nationwide percentage, and his 60 percent of the vote among 18-29s in November 2012 was 9 percent above his 51-percent nationwide percentage. Yes, the two age groups aren’t quite commensurate, but the numbers still suggest that the gap between young voters and their elders is shrinking. In 2008, it was the widest we have seen in any presidential general election since 1972 — and we don’t have any exit-poll data before then. In the latest CNN/ORC poll, it was down near the level of statistical insignificance.

Why is Obamamania disappearing among the young? One reason: Only 40 percent approve his performance on the economy, slightly less than the 42 percent among all respondents. Many conservatives have been wondering when the economic woes of young Americans — the high rate of joblessness, crushing student loan debt for worthless degrees or no degree — would sour them on Obama. If the CNN/ORC poll is right, the time is now.

Important caveat: this is just one poll. It could be wrong or misleading. Even so, it’s interesting. Some analyst’s have been extrapolating Obama’s 66-percent number in 2008 far out into the future, suggesting we will become an overwhelmingly Democratic country. These numbers suggest that may not be so.