The National Football League is quickly losing its core audience marking a shift that could bring an end to the sport’s dominance, a new poll finds.

The WSJ/NBC poll found several things that should worry the NFL both for its near and long-term future. For instance, in the short-term, fans are paying less attention than ever to the NFL. But, more worrisome, in the long-term, parents are increasingly discouraging their children from playing football over concerns over the sport’s safety. The latter would tend to create fewer football fans into the future.

The effect does not seem to be localized, either. Fan interest in the NFL has dropped across the various demographics, including in the crucial growth demo of young males, according to the Wall Street Journal.

“The drop in interest spans age groups and the political spectrum—painting the picture of a sport that isn’t just experiencing a momentary dip, but a battle against fundamental questions about football’s future that have been building for years,” the Journal wrote.

On the heels of a contentious season, fans seem to have become fatigued by the NFL on a myriad of levels:

The problems are taking a heavy toll. Adults who report following the NFL closely have dropped 9% since 2014, the poll finds. More alarming for the league, however, is the makeup of the people moving away from the NFL in large numbers: Just 51% of men aged 18 to 49 say they follow the NFL closely, down from 75% four years ago. The poll did not ask respondents why their interest changed. The Journal/NBC News poll interviewed 900 adults from Jan. 13-17. The margin of error for the full sample was plus or minus 3.27 percentage points.

Interestingly, the drop-offs fell across both Republican and Democrat viewers, but interest fell more among Democrats. While Republican interest declined 14 percent, it fell even further at 16 percent among Democrats.

While all that is bad for the NFL today, the poll also found that the league has long-term troubles on the horizon:

Beyond the scope of the NFL, the poll also revealed that parents are increasingly uncomfortable with the idea of their kids playing football, prompted by a surge in information about the dangers of head injuries. In 2014, 40% of mothers said they would encourage their child to play a sport other than football due to concerns about concussions. That figure has now climbed to 53%. Democrats, the poll found, expressed these concerns with head injuries more frequently than Republicans. … Even people without kids in their households appear to harbor doubts about football, with 49% saying they would encourage their child to play another sport, up from 43% in 2014. Roberts described this data as “a flashing yellow light,” since robust youth participation in a sport typically correlates with a larger adult fan base.

With fewer children joining the sport, this could reduce the number of new fans who might otherwise have come to the NFL when they grow up.

Fans are also skeptical about whether or not the NFL is taking sufficient steps to assure player safety. A recent poll found that only 47 percent say the league is taking meaningful steps to reduce concussions. That is down from the 59 percent who approved of the NFL’s actions on the matter in 2014.

Follow Warner Todd Huston on Twitter @warnerthuston.