NEW YORK >> Roger Ailes built the Fox News Channel into a ratings juggernaut, one that successfully presented a conservative alternative to mainstream news and garnered a large new audience in the Age of Trump.

But you don’t have to look too far down the road to see big challenges that have nothing to do with Ailes’ untimely departure .

While Fox has been the top-rated U.S. cable-news channel for 14 years, overall cable news audiences have been shrinking outside of presidential elections. More than half of Fox’s viewers are over 65, says data tracker Nielsen, compared to just 15 percent of Americans as a whole. They’re also more conservative than the general public, at a time when younger generations are trending more liberal, according to Pew . And it’s lagging in the digital efforts that many analysts consider key to attracting young people.

TV remains the dominant news source, but smartphone-addicted younger people are spending less time with it. Some 84 percent of 18-to-29-year-olds get news from social media like Facebook, and increasingly on their phones, according to Pew Research Center. Research firm eMarketer has predicted that digital ad spending will surpass TV ad spending in the U.S. next year for the first time.

“Fox News has been far more of a TV-centric business than a web or mobile business, if you compare it even to CNN,” said BTIG analyst Rich Greenfield. He pointed out as one example CNN’s spot on Snapchat’s Discover page, which spools up video and quick-read articles from media companies. Snapchat, a messaging app, is a blockbuster hit with young adults and teenagers.

And even if they were watching TV, the young people advertisers identify more as Democrats than Republicans by a 54-30 margin, according to a GenForward poll . They may not want to watch a channel so identified with conservatives.

None of that means Fox is likely to fade anytime soon. Demographic change moves slowly, and the channel’s strategy has been extraordinarily successful in a TV-centric world, earning it a core group of intensely loyal viewers that drew advertisers and made it a must-have for cable providers. Bernstein Research analyst Todd Juenger says in a research note that Fox News viewers are so addicted they’d be more likely to switch cable providers than give up the channel.

Some analysts scoff at the notion that Fox News has a problem with younger viewers.

“There’s a lot of concern in professional media circles that Fox (News) is going to disintegrate because it has an old audience,” said DePauw University media studies professor Jeffrey McCall. “I don’t think the brand is going to go away.” Fox’s ability to position itself as a news source that’s an alternative to the mainstream media has staying power, he says.

McCall also suggests that millennials might grow more conservative as they age. That common notion, however, clashes with academic findings that suggest political identity tends to gel in early adulthood.

Fox has done some digital experiments, including a live Q&A on Facebook during the GOP debate it aired last August, which drew a startling 24 million viewers (just less than the Grammys). It’s also streaming video on Facebook from this week’s Republican National Convention.

While those may not be as ambitious as rival efforts, analysts like McCall suggest that may not matter much to Fox right now, given its older audience. Those viewers aren’t “the kind of people who are going to be getting news off Twitter in same way as someone in their 30s or 40s,” he said.

Fox News did not answer questions for this story about its digital efforts.