About two-thirds of the way into media writer Michael Woolf’s Vanity Fair column, “The Man Who Ate the G.O.P.,” on the conundrum of Rush Limbaugh’s dual role as GOP party boss and hate radio megastar, this demographic nugget about the conservative media audience caught my eye:

Arguably no message apparatus like [Limbaugh's show] exists in the nation, except, perhaps, at the White House (or in Oprah — whose position with American women is curiously analogous to Rush’s position with American conservatives). It is concentrated and extraordinary power.

Except that this power ought to be ending. It ought to all be on the wane. It is not just the Obama victory and the magnitude of his approval ratings. It is not just that the gravity of the economic crisis, with historic unemployment rates, means it’s a lot harder to get people excited about Reagan-and-Rush-esque hands-off government.

It is, rather, a crueler demographic point. The dirty little secret of conservative talk radio is that the average age of listeners is 67 and rising, according to [Jon Sinton, founding president of Air America] — the Fox News audience, likewise, is in its mid-60s: “What sort of continuing power do you have as your audience strokes out?”

Only dinosaurs listen to radio these days, and it’s doubtful many people under 50 even know AM radio exists, so it shouldn’t be surprising that the average age of right-wing radio listeners is 67. It’s also truly not shocking that this demographic is also predominantly male. According to a Pew study in February, 72 percent of Limbaugh’s elderly listeners are men and thus are statistically likely to “stroke out” sometime in Pres. Obama’s second term, assuming he wins one.

However, television viewership trounces radio audiences in every demographic, so the fact that the average age of FNC viewers is, well, retired could have huge ramifications on the political playing field over the next decade.

It took some googling but I found a reliable source that confirms that during the 2007-2008 television season, the most recent season for which figures are available, the average age of Fox News viewers was 65:

According to a study released by Magna Global’s Steve Sternberg, the five broadcast nets’ average live median age (in other words, not including delayed DVR viewing) was 50 last season. That’s the oldest ever since Sternberg started analyzing median age more than a decade ago — and the first time the nets’ median age was outside of the vaunted 18-49 demo…

Among ad-supported cable nets, the news nets (along with older-skewing Hallmark Channel, Golf Channel and GSN’s daytime sked) sport the most gray, with Fox News Channel’s daytime and primetime skeds the absolute oldest, clocking in with a median age above 65. (Emphasis added.)

By the way, MSNBC’s “Countdown with Keith Olbermann” does the best in cable news primetime among the most desirable younger demographic, but according to numbers from last season, the average “Countdown” viewer is 59 years old, and 55 percent of its audience is male.