Every perceptive American knows that Fox News isn't an objective information source, but rather a propaganda conduit for tea party extremists and far-right Republicans. Former NBC CEO Jeff Zucker called it a GOP wing "masquerading as a cable-news channel."However, national writer Frank Rich says Fox actually is dwindling to a fringe watched solely by aging white conservatives -- hard-liners who embrace the channel's agenda -- and ignored by younger Americans.For example, Rich writes in New York magazine:"Every year, Fox News whips up some phantom 'war on Christmas' plotted by what the network's blowhard-in-chief Bill O'Reilly calls 'secular progressives.'"The latest uproar arose because black writer Aisha Harris joked that Santa should be "recast as a penguin for the sake of racial inclusiveness." The joke triggered Fox fire, with news anchor Megyn Kelly declaring that "Santa just is white" and "Jesus was a white man, too." Left-wing commentators denounced the right-wing denunciation.But Rich says liberals should shrug off Fox as a mere fringe, which sways nobody except the already-persuaded. Although Fox has more viewers than other cable channels, that field is small."Fox draws just over a million viewers in prime time -- a pittance and a niche next to even the ever-declining network newscasts, of which the lowest-rated (CBS Evening News) still can attract a nightly audience as large as 8 million," he said.In other words, Fox has 1 million solid members of "Fox nation" -- all of them guaranteed to vote Republican -- but America has more than 200 million other adults.Only 1.1 percent of Fox viewers are black -- "as opposed to 25 percent for MSNBC, 14 percent for CNN and an average of roughly 12 percent for the three broadcast networks' evening news programs," Rich wrote. Lily-white Fox loyalists are "happy to be cocooned in an echo chamber" hearing their own views reinforced.Also, the average age of a Fox watcher is 68, somewhat higher than the rate for other channels. "Fox is in essence a retirement community," Rich said.All branches of television are "hemorrhaging young viewers" as the next generation turns to iPads and smart phones. Fox will keep retreating like the others.Meanwhile, Fox's "chauvinistic Christianity" -- which embraced Duck Dynasty fundamentalists who likened gay sex to bestiality -- "is hardly an inducement to a younger America that is eschewing religious affiliation in numbers larger than any in the history of Pew polling," Rich wrote.There you have it: Fox News will continue to be the voice of a fringe of aging white conservatives, but it has little to do with mainstream America.